forked from itwanger/toBeBetterJavaer
-
Notifications
You must be signed in to change notification settings - Fork 0
/
equals-hashcode.html
161 lines (151 loc) · 133 KB
/
equals-hashcode.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
<!doctype html>
<html lang="zh-CN" data-theme="light">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width,initial-scale=1" />
<meta name="generator" content="VuePress 2.0.0-beta.67" />
<meta name="theme" content="VuePress Theme Hope" />
<meta name="keywords" content="Java,Java SE,Java基础,Java教程,二哥的Java进阶之路,Java进阶之路,Java入门,教程,java,hashcode,equals"><meta property="og:url" content="https://javabetter.cn/basic-extra-meal/equals-hashcode.html"><meta property="og:site_name" content="二哥的Java进阶之路"><meta property="og:title" content="为什么重写equals方法的时候必须要重写hashCode方法？"><meta property="og:description" content="二哥的Java进阶之路，小白的零基础Java教程，从入门到进阶，为什么重写equals方法的时候必须要重写hashCode方法"><meta property="og:type" content="article"><meta property="og:locale" content="zh-CN"><meta property="og:updated_time" content="2023-12-08T12:03:00.000Z"><meta property="article:author" content="沉默王二"><meta property="article:tag" content="Java重要知识点"><meta property="article:modified_time" content="2023-12-08T12:03:00.000Z"><script type="application/ld+json">{"@context":"https://schema.org","@type":"Article","headline":"为什么重写equals方法的时候必须要重写hashCode方法？","image":[""],"dateModified":"2023-12-08T12:03:00.000Z","author":[{"@type":"Person","name":"沉默王二","url":"/about-the-author/"}]}</script><meta name="robots" content="all"><meta name="author" content="沉默王二"><meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate"><meta http-equiv="Pragma" content="no-cache"><meta http-equiv="Expires" content="0"><meta name="apple-mobile-web-app-capable" content="yes"><script>
var _hmt = _hmt || [];
(function() {
var hm = document.createElement("script");
hm.src = "https://hm.baidu.com/hm.js?5230ac143650bf5eb3c14f3fb9b1d3ec";
var s = document.getElementsByTagName("script")[0];
s.parentNode.insertBefore(hm, s);
})();
</script><link rel="stylesheet" href="//at.alicdn.com/t/font_3180624_7cy10l7jqqh.css"><link rel="icon" href="https://cdn.tobebetterjavaer.com/tobebetterjavaer/images/favicon.ico"><link rel="icon" href="/assets/icon/chrome-mask-512.png" type="image/png" sizes="512x512"><link rel="icon" href="/assets/icon/chrome-mask-192.png" type="image/png" sizes="192x192"><link rel="icon" href="/assets/icon/chrome-512.png" type="image/png" sizes="512x512"><link rel="icon" href="/assets/icon/chrome-192.png" type="image/png" sizes="192x192"><link rel="manifest" href="/manifest.webmanifest" crossorigin="use-credentials"><meta name="theme-color" content="#096dd9"><link rel="apple-touch-icon" href="/assets/icon/apple-icon-152.png"><meta name="apple-mobile-web-app-status-bar-style" content="black"><meta name="msapplication-TileImage" content="/assets/icon/ms-icon-144.png"><meta name="msapplication-TileColor" content="#ffffff"><meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no, viewport-fit=cover"><title>为什么重写equals方法的时候必须要重写hashCode方法？ | 二哥的Java进阶之路</title><meta name="description" content="二哥的Java进阶之路，小白的零基础Java教程，从入门到进阶，为什么重写equals方法的时候必须要重写hashCode方法">
<style>
:root {
--bg-color: #fff;
}
html[data-theme="dark"] {
--bg-color: #1d1e1f;
}
html,
body {
background: var(--bg-color);
}
</style>
<script>
const userMode = localStorage.getItem("vuepress-theme-hope-scheme");
const systemDarkMode =
window.matchMedia &&
window.matchMedia("(prefers-color-scheme: dark)").matches;
if (userMode === "dark" || (userMode !== "light" && systemDarkMode)) {
document.documentElement.setAttribute("data-theme", "dark");
}
</script>
<link rel="preload" href="/assets/style-ec31d3d3.css" as="style"><link rel="stylesheet" href="/assets/style-ec31d3d3.css">
<link rel="modulepreload" href="/assets/app-dea8ffe7.js"><link rel="modulepreload" href="/assets/equals-hashcode.html-1ce67509.js"><link rel="modulepreload" href="/assets/plugin-vue_export-helper-c27b6911.js"><link rel="modulepreload" href="/assets/equals-hashcode.html-b4e82932.js"><link rel="prefetch" href="/assets/index.html-6896c647.js" as="script"><link rel="prefetch" href="/assets/blog.html-f1f40691.js" as="script"><link rel="prefetch" href="/assets/home.html-a403fdc1.js" as="script"><link rel="prefetch" href="/assets/bzhan-10wan.html-3a3b1bb2.js" as="script"><link rel="prefetch" href="/assets/csdn-1000wan.html-4f2d080d.js" as="script"><link rel="prefetch" href="/assets/index.html-c060d9c7.js" as="script"><link rel="prefetch" href="/assets/zhihu-1000wan.html-462c982c.js" as="script"><link rel="prefetch" href="/assets/array.html-36da03a6.js" as="script"><link rel="prefetch" href="/assets/double-array.html-59d0cb0d.js" as="script"><link rel="prefetch" href="/assets/print.html-b124a5fd.js" as="script"><link rel="prefetch" href="/assets/basic-data-type.html-425f11fd.js" as="script"><link rel="prefetch" href="/assets/basic-exercise.html-d3790bcb.js" as="script"><link rel="prefetch" href="/assets/bigdecimal-biginteger.html-612adcb4.js" as="script"><link rel="prefetch" href="/assets/flow-control.html-5c7cd9dd.js" as="script"><link rel="prefetch" href="/assets/javadoc.html-e8207ba9.js" as="script"><link rel="prefetch" href="/assets/operator.html-123d5f77.js" as="script"><link rel="prefetch" href="/assets/type-cast.html-16ecbcb3.js" as="script"><link rel="prefetch" href="/assets/48-keywords.html-981e3a53.js" as="script"><link rel="prefetch" href="/assets/Overriding.html-8492a9cc.js" as="script"><link rel="prefetch" href="/assets/annotation.html-90f8578c.js" as="script"><link rel="prefetch" href="/assets/box.html-ec79b8ae.js" as="script"><link rel="prefetch" href="/assets/class-object.html-53a5bdf9.js" as="script"><link rel="prefetch" href="/assets/comparable-omparator.html-e1bfd760.js" as="script"><link rel="prefetch" href="/assets/deep-copy.html-7f574982.js" as="script"><link rel="prefetch" href="/assets/enum.html-af30e4ab.js" as="script"><link rel="prefetch" href="/assets/fanshe.html-02328c72.js" as="script"><link rel="prefetch" href="/assets/generic.html-6ae4cb05.js" as="script"><link rel="prefetch" href="/assets/hashcode.html-70d32908.js" as="script"><link rel="prefetch" href="/assets/immutable.html-64a87d92.js" as="script"><link rel="prefetch" href="/assets/instanceof-jvm.html-078aa552.js" as="script"><link rel="prefetch" href="/assets/instanceof.html-c9121a58.js" as="script"><link rel="prefetch" href="/assets/int-cache.html-d6d10629.js" as="script"><link rel="prefetch" href="/assets/java-naming.html-e9ee774d.js" as="script"><link rel="prefetch" href="/assets/java-unicode.html-10433726.js" as="script"><link rel="prefetch" href="/assets/jdk-while-for-wuxian-xunhuan.html-ee4f7686.js" as="script"><link rel="prefetch" href="/assets/jdk9-char-byte-string.html-608cfe76.js" as="script"><link rel="prefetch" href="/assets/override-overload.html-505ea6b3.js" as="script"><link rel="prefetch" href="/assets/pass-by-value.html-15acd903.js" as="script"><link rel="prefetch" href="/assets/true-generic.html-fb51fe4e.js" as="script"><link rel="prefetch" href="/assets/varables.html-30b43a11.js" as="script"><link rel="prefetch" href="/assets/beijing.html-d6945ee0.js" as="script"><link rel="prefetch" href="/assets/chengdu.html-e824cea2.js" as="script"><link rel="prefetch" href="/assets/guangzhou.html-36746483.js" as="script"><link rel="prefetch" href="/assets/hangzhou.html-64b59f16.js" as="script"><link rel="prefetch" href="/assets/jinan.html-6452b409.js" as="script"><link rel="prefetch" href="/assets/nanjing.html-525f0ed8.js" as="script"><link rel="prefetch" href="/assets/qingdao.html-79e09121.js" as="script"><link rel="prefetch" href="/assets/shenzhen.html-d67ca4ae.js" as="script"><link rel="prefetch" href="/assets/suzhou.html-fe1af157.js" as="script"><link rel="prefetch" href="/assets/wuhan.html-a46f4845.js" as="script"><link rel="prefetch" href="/assets/xian.html-52c1bbdc.js" as="script"><link rel="prefetch" href="/assets/zhengzhou.html-fa55ea38.js" as="script"><link rel="prefetch" href="/assets/PriorityQueue.html-7dda40ec.js" as="script"><link rel="prefetch" href="/assets/WeakHashMap.html-034f99ad.js" as="script"><link rel="prefetch" href="/assets/arraydeque.html-e0054edd.js" as="script"><link rel="prefetch" href="/assets/arraylist.html-f8eeecb3.js" as="script"><link rel="prefetch" href="/assets/fail-fast.html-33ff838c.js" as="script"><link rel="prefetch" href="/assets/gailan.html-c6e5d650.js" as="script"><link rel="prefetch" href="/assets/hashmap.html-3d9f5bf5.js" as="script"><link rel="prefetch" href="/assets/iterator-iterable.html-97b4585f.js" as="script"><link rel="prefetch" href="/assets/linkedhashmap.html-dbc7e2d6.js" as="script"><link rel="prefetch" href="/assets/linkedlist.html-2ea2e9bd.js" as="script"><link rel="prefetch" href="/assets/list-war-2.html-841934b5.js" as="script"><link rel="prefetch" href="/assets/time-complexity.html-3d3dbc8c.js" as="script"><link rel="prefetch" href="/assets/treemap.html-c88192e7.js" as="script"><link rel="prefetch" href="/assets/Objects.html-0d65caf8.js" as="script"><link rel="prefetch" href="/assets/StringUtils.html-56106d87.js" as="script"><link rel="prefetch" href="/assets/arrays.html-249b8e80.js" as="script"><link rel="prefetch" href="/assets/collections.html-55e2172e.js" as="script"><link rel="prefetch" href="/assets/guava.html-b178f406.js" as="script"><link rel="prefetch" href="/assets/hutool.html-0a4f348e.js" as="script"><link rel="prefetch" href="/assets/scanner.html-129eb6a2.js" as="script"><link rel="prefetch" href="/assets/utils.html-bfa3ed99.js" as="script"><link rel="prefetch" href="/assets/os.html-02bf3c7f.js" as="script"><link rel="prefetch" href="/assets/wangluo.html-ad5d42dd.js" as="script"><link rel="prefetch" href="/assets/history.html-1d239f57.js" as="script"><link rel="prefetch" href="/assets/javabooks.html-1a9103a1.js" as="script"><link rel="prefetch" href="/assets/learn-jianyi.html-49096c6c.js" as="script"><link rel="prefetch" href="/assets/nicearticle.html-a974a3b4.js" as="script"><link rel="prefetch" href="/assets/rumen.html-a3d59ffd.js" as="script"><link rel="prefetch" href="/assets/gailan.html-c4fc478b.js" as="script"><link rel="prefetch" href="/assets/npe.html-4ee390a0.js" as="script"><link rel="prefetch" href="/assets/shijian.html-d1b5090f.js" as="script"><link rel="prefetch" href="/assets/try-catch-xingneng.html-118b6a1b.js" as="script"><link rel="prefetch" href="/assets/try-with-resources.html-39ed2b10.js" as="script"><link rel="prefetch" href="/assets/git-qiyuan.html-fe8bd069.js" as="script"><link rel="prefetch" href="/assets/progit.html-0354f264.js" as="script"><link rel="prefetch" href="/assets/DBeaver.html-fb9fd30b.js" as="script"><link rel="prefetch" href="/assets/brew.html-9d00d447.js" as="script"><link rel="prefetch" href="/assets/chiner.html-fdcf8df4.js" as="script"><link rel="prefetch" href="/assets/choco.html-97dd9711.js" as="script"><link rel="prefetch" href="/assets/fastjson.html-6d387440.js" as="script"><link rel="prefetch" href="/assets/forest.html-4e960d36.js" as="script"><link rel="prefetch" href="/assets/gson.html-04f378ab.js" as="script"><link rel="prefetch" href="/assets/jackson.html-da8d6e2f.js" as="script"><link rel="prefetch" href="/assets/junit.html-813748e0.js" as="script"><link rel="prefetch" href="/assets/knife4j.html-fb7e6f1e.js" as="script"><link rel="prefetch" href="/assets/log4j.html-a1988ef9.js" as="script"><link rel="prefetch" href="/assets/log4j2.html-043b7035.js" as="script"><link rel="prefetch" href="/assets/logback.html-6231a565.js" as="script"><link rel="prefetch" href="/assets/others.html-b58cbfa3.js" as="script"><link rel="prefetch" href="/assets/slf4j.html-eaf0a86c.js" as="script"><link rel="prefetch" href="/assets/tabby.html-ceb52e1f.js" as="script"><link rel="prefetch" href="/assets/warp.html-46cfc7a7.js" as="script"><link rel="prefetch" href="/assets/windterm.html-8c6d96be.js" as="script"><link rel="prefetch" href="/assets/4-debug-skill.html-1bb59e4c.js" as="script"><link rel="prefetch" href="/assets/shenji-chajian-10.html-1613604d.js" as="script"><link rel="prefetch" href="/assets/xechat.html-6ab8484a.js" as="script"><link rel="prefetch" href="/assets/dubbo-17.html-1d5d7476.js" as="script"><link rel="prefetch" href="/assets/java-34.html-6b3ceba9.js" as="script"><link rel="prefetch" href="/assets/java-basic-baguwen.html-5774e2c3.js" as="script"><link rel="prefetch" href="/assets/java-hashmap-13.html-9f66f862.js" as="script"><link rel="prefetch" href="/assets/java-jvm-baguwen.html-b89e5b2e.js" as="script"><link rel="prefetch" href="/assets/java-thread-baguwen.html-eb5d9fe2.js" as="script"><link rel="prefetch" href="/assets/kafka-40.html-c0d7ff98.js" as="script"><link rel="prefetch" href="/assets/mianshiguan-bigfile-miaochuan.html-e63a649f.js" as="script"><link rel="prefetch" href="/assets/mianshiguan-fenkufenbiao.html-5c10537f.js" as="script"><link rel="prefetch" href="/assets/mianshiguan-youhuiquan.html-072617d6.js" as="script"><link rel="prefetch" href="/assets/mysql-60.html-55c78692.js" as="script"><link rel="prefetch" href="/assets/mysql-suoyin-15.html-284a563a.js" as="script"><link rel="prefetch" href="/assets/nginx-40.html-c5a74461.js" as="script"><link rel="prefetch" href="/assets/redis-12.html-b4f9a5f0.js" as="script"><link rel="prefetch" href="/assets/Serializbale.html-3aff2791.js" as="script"><link rel="prefetch" href="/assets/buffer.html-665f4b0d.js" as="script"><link rel="prefetch" href="/assets/char-byte.html-d8a6ba00.js" as="script"><link rel="prefetch" href="/assets/file-path.html-76566497.js" as="script"><link rel="prefetch" href="/assets/print.html-80126690.js" as="script"><link rel="prefetch" href="/assets/reader-writer.html-9f335c22.js" as="script"><link rel="prefetch" href="/assets/serialize.html-99755726.js" as="script"><link rel="prefetch" href="/assets/shangtou.html-22a723f5.js" as="script"><link rel="prefetch" href="/assets/stream.html-91d8bc25.js" as="script"><link rel="prefetch" href="/assets/transient.html-e0cd180e.js" as="script"><link rel="prefetch" href="/assets/Lambda.html-c17cd2ca.js" as="script"><link rel="prefetch" href="/assets/java14.html-4626b229.js" as="script"><link rel="prefetch" href="/assets/optional.html-24fb31d4.js" as="script"><link rel="prefetch" href="/assets/stream.html-bc62142a.js" as="script"><link rel="prefetch" href="/assets/asm.html-75a99a47.js" as="script"><link rel="prefetch" href="/assets/bytecode.html-e8f928c3.js" as="script"><link rel="prefetch" href="/assets/class-file-jiegou.html-14a7b070.js" as="script"><link rel="prefetch" href="/assets/class-load.html-a941da78.js" as="script"><link rel="prefetch" href="/assets/compile-jdk.html-79739861.js" as="script"><link rel="prefetch" href="/assets/cpu-percent-100.html-d1c1c3cf.js" as="script"><link rel="prefetch" href="/assets/garbage-collector.html-0300af73.js" as="script"><link rel="prefetch" href="/assets/gc-collector.html-31bf98a8.js" as="script"><link rel="prefetch" href="/assets/gc.html-0338b3bb.js" as="script"><link rel="prefetch" href="/assets/how-jvm-run-zijiema-zhiling.html-44628196.js" as="script"><link rel="prefetch" href="/assets/how-run-java-code.html-d6298a9c.js" as="script"><link rel="prefetch" href="/assets/hsdb.html-027fac52.js" as="script"><link rel="prefetch" href="/assets/jit.html-0bbc9bec.js" as="script"><link rel="prefetch" href="/assets/meituan-9-gc.html-950b1687.js" as="script"><link rel="prefetch" href="/assets/neicun-jiegou.html-f3eb7009.js" as="script"><link rel="prefetch" href="/assets/oom.html-ab4f847e.js" as="script"><link rel="prefetch" href="/assets/problem-tools.html-86cdaf1a.js" as="script"><link rel="prefetch" href="/assets/index.html-82f93945.js" as="script"><link rel="prefetch" href="/assets/stack-frame.html-aa4e2264.js" as="script"><link rel="prefetch" href="/assets/tujie-gc.html-ebd90f16.js" as="script"><link rel="prefetch" href="/assets/vm-stack-register.html-525c9d47.js" as="script"><link rel="prefetch" href="/assets/what-happen-when-javac.html-a8630847.js" as="script"><link rel="prefetch" href="/assets/what-is-jvm.html-78cc38a9.js" as="script"><link rel="prefetch" href="/assets/whereis-the-object.html-d71973da.js" as="script"><link rel="prefetch" href="/assets/zijiema-zhiling.html-f9f2d56c.js" as="script"><link rel="prefetch" href="/assets/zongjie.html-1dd32909.js" as="script"><link rel="prefetch" href="/assets/auto-generator.html-e4bf00bb.js" as="script"><link rel="prefetch" href="/assets/index.html-c6d7a628.js" as="script"><link rel="prefetch" href="/assets/yuneban-wangyiyunyinyue.html-1548f16c.js" as="script"><link rel="prefetch" href="/assets/maven.html-b39b7158.js" as="script"><link rel="prefetch" href="/assets/chengxyspnhxagzl.html-a1566b96.js" as="script"><link rel="prefetch" href="/assets/huanxgzl.html-819243e6.js" as="script"><link rel="prefetch" href="/assets/quzjlsspdx.html-e96c61f8.js" as="script"><link rel="prefetch" href="/assets/shanganaliyun.html-29da0fc1.js" as="script"><link rel="prefetch" href="/assets/shezynmjfxhelmtttjddd.html-f8faf762.js" as="script"><link rel="prefetch" href="/assets/xuelybdzheloffer.html-9d010034.js" as="script"><link rel="prefetch" href="/assets/zheisnylzldhzd.html-9ac69874.js" as="script"><link rel="prefetch" href="/assets/api-wangguan.html-1e0bf31c.js" as="script"><link rel="prefetch" href="/assets/rumen.html-c4a3df17.js" as="script"><link rel="prefetch" href="/assets/100-budiushi.html-569a81fa.js" as="script"><link rel="prefetch" href="/assets/kafka.html-79415df6.js" as="script"><link rel="prefetch" href="/assets/rabbitmq-rumen.html-d6977dde.js" as="script"><link rel="prefetch" href="/assets/install.html-554652c1.js" as="script"><link rel="prefetch" href="/assets/lijie-shiwu.html-b76f32c1.js" as="script"><link rel="prefetch" href="/assets/redis-shuju-yizhixing.html-918357a2.js" as="script"><link rel="prefetch" href="/assets/shiwu-shixian.html-7e02ddf3.js" as="script"><link rel="prefetch" href="/assets/rumen.html-9c05a8e2.js" as="script"><link rel="prefetch" href="/assets/nginx.html-74b3c8aa.js" as="script"><link rel="prefetch" href="/assets/BIONIOAIO.html-2f2c80b6.js" as="script"><link rel="prefetch" href="/assets/buffer-channel.html-88cecb4f.js" as="script"><link rel="prefetch" href="/assets/moxing.html-230346e6.js" as="script"><link rel="prefetch" href="/assets/network-connect.html-1c9e8b0d.js" as="script"><link rel="prefetch" href="/assets/nio-better-io.html-1905f5e7.js" as="script"><link rel="prefetch" href="/assets/paths-files.html-513db619.js" as="script"><link rel="prefetch" href="/assets/abstract-vs-interface.html-2afbf4f3.js" as="script"><link rel="prefetch" href="/assets/abstract.html-0dc72e83.js" as="script"><link rel="prefetch" href="/assets/access-control.html-1d997502.js" as="script"><link rel="prefetch" href="/assets/code-init.html-4a488348.js" as="script"><link rel="prefetch" href="/assets/construct.html-13b725a0.js" as="script"><link rel="prefetch" href="/assets/encapsulation-inheritance-polymorphism.html-acbafdc9.js" as="script"><link rel="prefetch" href="/assets/encapsulation.html-7fd2c50a.js" as="script"><link rel="prefetch" href="/assets/extends-bigsai.html-aeb190f0.js" as="script"><link rel="prefetch" href="/assets/final.html-8116fb58.js" as="script"><link rel="prefetch" href="/assets/inner-class.html-5b6833fd.js" as="script"><link rel="prefetch" href="/assets/interface.html-229b9d7f.js" as="script"><link rel="prefetch" href="/assets/method.html-c3489033.js" as="script"><link rel="prefetch" href="/assets/native-method.html-4a5d20af.js" as="script"><link rel="prefetch" href="/assets/object-class.html-8060b8d4.js" as="script"><link rel="prefetch" href="/assets/package.html-f4bc06cb.js" as="script"><link rel="prefetch" href="/assets/polymorphism.html-dca0f598.js" as="script"><link rel="prefetch" href="/assets/static.html-d9a2201f.js" as="script"><link rel="prefetch" href="/assets/this-super.html-4ce10f05.js" as="script"><link rel="prefetch" href="/assets/var.html-67a5467f.js" as="script"><link rel="prefetch" href="/assets/IDEA-install-config.html-10e061f7.js" as="script"><link rel="prefetch" href="/assets/hello-world.html-b60cdafd.js" as="script"><link rel="prefetch" href="/assets/java-can-do-what.html-7db86990.js" as="script"><link rel="prefetch" href="/assets/java-history.html-c5514112.js" as="script"><link rel="prefetch" href="/assets/jdk-install-config.html-1c34f74a.js" as="script"><link rel="prefetch" href="/assets/index.html-2adfe042.js" as="script"><link rel="prefetch" href="/assets/what-is-java.html-9cb4fc8e.js" as="script"><link rel="prefetch" href="/assets/ali-java-shouce.html-f0404cbb.js" as="script"><link rel="prefetch" href="/assets/bat-shuati.html-a94acac5.js" as="script"><link rel="prefetch" href="/assets/github-java-jiaocheng-115-star.html-03ef8c34.js" as="script"><link rel="prefetch" href="/assets/java-concurrent.html-3327eb57.js" as="script"><link rel="prefetch" href="/assets/java-leetcode.html-7a961269.js" as="script"><link rel="prefetch" href="/assets/java.html-c88bc6e8.js" as="script"><link rel="prefetch" href="/assets/jianli.html-6290649d.js" as="script"><link rel="prefetch" href="/assets/os.html-5063f776.js" as="script"><link rel="prefetch" href="/assets/progit.html-62b68ce7.js" as="script"><link rel="prefetch" href="/assets/programmer-111.html-a7b4925f.js" as="script"><link rel="prefetch" href="/assets/index.html-ce4f28d7.js" as="script"><link rel="prefetch" href="/assets/shejimoshi.html-52dab855.js" as="script"><link rel="prefetch" href="/assets/yuanyifeng-c-language.html-af958bf3.js" as="script"><link rel="prefetch" href="/assets/install.html-eff0d7ce.js" as="script"><link rel="prefetch" href="/assets/redis-springboot.html-dec4eea6.js" as="script"><link rel="prefetch" href="/assets/rumen.html-38166c5d.js" as="script"><link rel="prefetch" href="/assets/xuebeng-chuantou-jichuan.html-40620940.js" as="script"><link rel="prefetch" href="/assets/computer-base.html-e160827f.js" as="script"><link rel="prefetch" href="/assets/http.html-2cdb2c0d.js" as="script"><link rel="prefetch" href="/assets/network-base.html-1b2d21c2.js" as="script"><link rel="prefetch" href="/assets/socket.html-89522d1e.js" as="script"><link rel="prefetch" href="/assets/Filter-Interceptor-Listener.html-080e449d.js" as="script"><link rel="prefetch" href="/assets/aop-log.html-b8b34fa1.js" as="script"><link rel="prefetch" href="/assets/cors.html-9a2d2ccb.js" as="script"><link rel="prefetch" href="/assets/docker.html-900ccc73.js" as="script"><link rel="prefetch" href="/assets/initializr.html-921624d3.js" as="script"><link rel="prefetch" href="/assets/ioc.html-64270fb3.js" as="script"><link rel="prefetch" href="/assets/jpa.html-dd4e23b1.js" as="script"><link rel="prefetch" href="/assets/jwt.html-5a88ec3f.js" as="script"><link rel="prefetch" href="/assets/linux-codingmore-run.html-8fa491e7.js" as="script"><link rel="prefetch" href="/assets/logback.html-5664afe0.js" as="script"><link rel="prefetch" href="/assets/lombok.html-a2b4ed5f.js" as="script"><link rel="prefetch" href="/assets/macos-codingmore-run.html-8f3d9d93.js" as="script"><link rel="prefetch" href="/assets/mybatis.html-fb39fc77.js" as="script"><link rel="prefetch" href="/assets/mysql-druid.html-9d79f586.js" as="script"><link rel="prefetch" href="/assets/oss.html-ccaef112.js" as="script"><link rel="prefetch" href="/assets/quartz.html-2940c054.js" as="script"><link rel="prefetch" href="/assets/springtask.html-f3c706ea.js" as="script"><link rel="prefetch" href="/assets/swagger.html-817a0df7.js" as="script"><link rel="prefetch" href="/assets/thymeleaf.html-d30ee7a2.js" as="script"><link rel="prefetch" href="/assets/tomcat.html-12c9c35e.js" as="script"><link rel="prefetch" href="/assets/transaction.html-2e12fa03.js" as="script"><link rel="prefetch" href="/assets/validator.html-f791dd01.js" as="script"><link rel="prefetch" href="/assets/windows-codingmore-run.html-a6a87b6a.js" as="script"><link rel="prefetch" href="/assets/builder-buffer.html-51d3c37e.js" as="script"><link rel="prefetch" href="/assets/constant-pool.html-c15bdbbe.js" as="script"><link rel="prefetch" href="/assets/equals.html-e05d6be1.js" as="script"><link rel="prefetch" href="/assets/immutable.html-6407d753.js" as="script"><link rel="prefetch" href="/assets/intern.html-7366429d.js" as="script"><link rel="prefetch" href="/assets/join.html-e9eb59c9.js" as="script"><link rel="prefetch" href="/assets/split.html-e2314065.js" as="script"><link rel="prefetch" href="/assets/string-source.html-a8774a9e.js" as="script"><link rel="prefetch" href="/assets/buy-cloud-server.html-3bd1675f.js" as="script"><link rel="prefetch" href="/assets/buy-domain.html-90d3f256.js" as="script"><link rel="prefetch" href="/assets/https-domain.html-9106901d.js" as="script"><link rel="prefetch" href="/assets/install-baota-mianban.html-68226428.js" as="script"><link rel="prefetch" href="/assets/record-domain.html-eb97e19c.js" as="script"><link rel="prefetch" href="/assets/tobebetterjavaer-wangzhan-shangxian.html-1f37291c.js" as="script"><link rel="prefetch" href="/assets/tupian-zhuanlian.html-a1c20ae9.js" as="script"><link rel="prefetch" href="/assets/BlockingQueue.html-2080d791.js" as="script"><link rel="prefetch" href="/assets/ConcurrentHashMap.html-d8cee0a5.js" as="script"><link rel="prefetch" href="/assets/ConcurrentLinkedQueue.html-41267914.js" as="script"><link rel="prefetch" href="/assets/CopyOnWriteArrayList.html-7f264606.js" as="script"><link rel="prefetch" href="/assets/CountDownLatch.html-bec30bfb.js" as="script"><link rel="prefetch" href="/assets/LockSupport.html-98325974.js" as="script"><link rel="prefetch" href="/assets/ReentrantReadWriteLock.html-a4e0aff2.js" as="script"><link rel="prefetch" href="/assets/ScheduledThreadPoolExecutor.html-5003a104.js" as="script"><link rel="prefetch" href="/assets/ThreadLocal.html-c5f3c9cf.js" as="script"><link rel="prefetch" href="/assets/Unsafe.html-ed1a7c83.js" as="script"><link rel="prefetch" href="/assets/ali-executors.html-e0e3b6f6.js" as="script"><link rel="prefetch" href="/assets/aqs.html-3646bd7a.js" as="script"><link rel="prefetch" href="/assets/atomic.html-87c43513.js" as="script"><link rel="prefetch" href="/assets/callable-future-futuretask.html-a865bea7.js" as="script"><link rel="prefetch" href="/assets/cas.html-4b568f79.js" as="script"><link rel="prefetch" href="/assets/condition.html-71d7e4db.js" as="script"><link rel="prefetch" href="/assets/fork-join.html-04600b7a.js" as="script"><link rel="prefetch" href="/assets/jmm.html-23e57735.js" as="script"><link rel="prefetch" href="/assets/lock.html-07580e46.js" as="script"><link rel="prefetch" href="/assets/map.html-cb918448.js" as="script"><link rel="prefetch" href="/assets/pianxiangsuo.html-97c1f207.js" as="script"><link rel="prefetch" href="/assets/pool.html-53e954b3.js" as="script"><link rel="prefetch" href="/assets/index.html-eb65e8db.js" as="script"><link rel="prefetch" href="/assets/reentrantLock.html-257c263e.js" as="script"><link rel="prefetch" href="/assets/shengchanzhe-xiaofeizhe.html-2900b5cf.js" as="script"><link rel="prefetch" href="/assets/suo.html-25ffef73.js" as="script"><link rel="prefetch" href="/assets/synchronized-1.html-59b53777.js" as="script"><link rel="prefetch" href="/assets/synchronized.html-1b1e425a.js" as="script"><link rel="prefetch" href="/assets/thread-bring-some-problem.html-f1d8e8bd.js" as="script"><link rel="prefetch" href="/assets/thread-group-and-thread-priority.html-d96ea2d3.js" as="script"><link rel="prefetch" href="/assets/thread-state-and-method.html-16ab48cc.js" as="script"><link rel="prefetch" href="/assets/volatile.html-3d4fb924.js" as="script"><link rel="prefetch" href="/assets/wangzhe-thread.html-bac72afe.js" as="script"><link rel="prefetch" href="/assets/why-need-thread.html-2f055e24.js" as="script"><link rel="prefetch" href="/assets/aliyun-shuaiguo-gongchengshi.html-a4b723b3.js" as="script"><link rel="prefetch" href="/assets/chadiansanhuo.html-32b9a4b5.js" as="script"><link rel="prefetch" href="/assets/chengxuyuannv-chonghui-java.html-1e43b407.js" as="script"><link rel="prefetch" href="/assets/daxue-nuli-jisuanji.html-1c7c9fd3.js" as="script"><link rel="prefetch" href="/assets/fumutuanju.html-58fc926c.js" as="script"><link rel="prefetch" href="/assets/20ren-it-quma.html-2253af1b.js" as="script"><link rel="prefetch" href="/assets/35-weiji.html-989f3eaa.js" as="script"><link rel="prefetch" href="/assets/408.html-9c67bc44.js" as="script"><link rel="prefetch" href="/assets/LearnCS-ByYourself.html-41c76a96.js" as="script"><link rel="prefetch" href="/assets/benkesheng-ali-tengxun.html-61762a45.js" as="script"><link rel="prefetch" href="/assets/chengxuyuan-fuye.html-07754bd4.js" as="script"><link rel="prefetch" href="/assets/electron-information-engineering.html-c9ba81a2.js" as="script"><link rel="prefetch" href="/assets/gaobingfa-jingyan-hsmcomputer.html-abe955ea.js" as="script"><link rel="prefetch" href="/assets/gaokao-zhiyuan-cs.html-a74f520b.js" as="script"><link rel="prefetch" href="/assets/hr-xinzi.html-c461d254.js" as="script"><link rel="prefetch" href="/assets/read-csapp.html-c81dbe58.js" as="script"><link rel="prefetch" href="/assets/ruhzfzdgzzcxcz.html-ac2ac670.js" as="script"><link rel="prefetch" href="/assets/test-programmer-read-books.html-c59f415a.js" as="script"><link rel="prefetch" href="/assets/xiaozhao-java-should-master.html-3b016e4f.js" as="script"><link rel="prefetch" href="/assets/algorithm.html-bc1bf956.js" as="script"><link rel="prefetch" href="/assets/android.html-13df7afa.js" as="script"><link rel="prefetch" href="/assets/bigdata.html-9da6e61f.js" as="script"><link rel="prefetch" href="/assets/c.html-76598af7.js" as="script"><link rel="prefetch" href="/assets/ccc.html-67ddde2d.js" as="script"><link rel="prefetch" href="/assets/donet.html-6d3a625b.js" as="script"><link rel="prefetch" href="/assets/go.html-26842a9b.js" as="script"><link rel="prefetch" href="/assets/lanqiaobei.html-4efe9d76.js" as="script"><link rel="prefetch" href="/assets/mysql.html-46d80b00.js" as="script"><link rel="prefetch" href="/assets/os.html-9f52053d.js" as="script"><link rel="prefetch" href="/assets/python.html-c90feb5c.js" as="script"><link rel="prefetch" href="/assets/qianduan.html-77a91ee4.js" as="script"><link rel="prefetch" href="/assets/index.html-bc80a12a.js" as="script"><link rel="prefetch" href="/assets/redis.html-b450161c.js" as="script"><link rel="prefetch" href="/assets/august.html-0b6d1f90.js" as="script"><link rel="prefetch" href="/assets/first.html-da35e9e7.js" as="script"><link rel="prefetch" href="/assets/java-mianshi-zhinan.html-6c05b755.js" as="script"><link rel="prefetch" href="/assets/jianli.html-b74c3d24.js" as="script"><link rel="prefetch" href="/assets/july.html-d321c3a0.js" as="script"><link rel="prefetch" href="/assets/june.html-73a1e8b1.js" as="script"><link rel="prefetch" href="/assets/map.html-caf41b74.js" as="script"><link rel="prefetch" href="/assets/may.html-84498c7a.js" as="script"><link rel="prefetch" href="/assets/mianshi.html-a4c02e87.js" as="script"><link rel="prefetch" href="/assets/paicoding.html-b366035d.js" as="script"><link rel="prefetch" href="/assets/index.html-705c3853.js" as="script"><link rel="prefetch" href="/assets/jibenjieshao.html-f28197ee.js" as="script"><link rel="prefetch" href="/assets/luoczbmsddyb.html-f5178ce0.js" as="script"><link rel="prefetch" href="/assets/miansmtgl.html-88986cc7.js" as="script"><link rel="prefetch" href="/assets/xzbztdncdlxgljsjq.html-843568aa.js" as="script"><link rel="prefetch" href="/assets/youdxzhhmjzlycfx.html-3e2e4207.js" as="script"><link rel="prefetch" href="/assets/zijxjjdyfqzgl.html-01477be0.js" as="script"><link rel="prefetch" href="/assets/javase.html-951d0cd7.js" as="script"><link rel="prefetch" href="/assets/collection.html-c0fcb04a.js" as="script"><link rel="prefetch" href="/assets/fenbushi.html-e332b925.js" as="script"><link rel="prefetch" href="/assets/javase.html-c8a82362.js" as="script"><link rel="prefetch" href="/assets/javathread.html-d213607b.js" as="script"><link rel="prefetch" href="/assets/jvm.html-b6a1b1d0.js" as="script"><link rel="prefetch" href="/assets/mybatis.html-c5e4ca4b.js" as="script"><link rel="prefetch" href="/assets/mysql.html-60e96142.js" as="script"><link rel="prefetch" href="/assets/network.html-28a40cea.js" as="script"><link rel="prefetch" href="/assets/nixi.html-c0144938.js" as="script"><link rel="prefetch" href="/assets/os.html-a0fb8f0d.js" as="script"><link rel="prefetch" href="/assets/redis.html-b239471f.js" as="script"><link rel="prefetch" href="/assets/rocketmq.html-86ff123e.js" as="script"><link rel="prefetch" href="/assets/spring.html-6c81fb39.js" as="script"><link rel="prefetch" href="/assets/weifuwu.html-85492537.js" as="script"><link rel="prefetch" href="/assets/jvm.html-dfcf4e0f.js" as="script"><link rel="prefetch" href="/assets/thread.html-92ad35e2.js" as="script"><link rel="prefetch" href="/assets/yitiaolong.html-3a9fd9b7.js" as="script"><link rel="prefetch" href="/assets/404.html-73858f58.js" as="script"><link rel="prefetch" href="/assets/index.html-e39f9947.js" as="script"><link rel="prefetch" href="/assets/index.html-522021f4.js" as="script"><link rel="prefetch" href="/assets/index.html-d3ba01c3.js" as="script"><link rel="prefetch" href="/assets/index.html-5dd50ac9.js" as="script"><link rel="prefetch" href="/assets/index.html-d40b6d34.js" as="script"><link rel="prefetch" href="/assets/index.html-431ec1b9.js" as="script"><link rel="prefetch" href="/assets/index.html-7dbe085d.js" as="script"><link rel="prefetch" href="/assets/index.html-24e8a73f.js" as="script"><link rel="prefetch" href="/assets/index.html-1575064b.js" as="script"><link rel="prefetch" href="/assets/index.html-2cbc852a.js" as="script"><link rel="prefetch" href="/assets/index.html-17787a20.js" as="script"><link rel="prefetch" href="/assets/index.html-6089ddb6.js" as="script"><link rel="prefetch" href="/assets/index.html-2d3a682a.js" as="script"><link rel="prefetch" href="/assets/index.html-5db156a2.js" as="script"><link rel="prefetch" href="/assets/index.html-ef7c0ff6.js" as="script"><link rel="prefetch" href="/assets/index.html-9cb6404f.js" as="script"><link rel="prefetch" href="/assets/index.html-a07e2b9c.js" as="script"><link rel="prefetch" href="/assets/index.html-e2551c5b.js" as="script"><link rel="prefetch" href="/assets/index.html-7cdc8698.js" as="script"><link rel="prefetch" href="/assets/index.html-49bd7cf7.js" as="script"><link rel="prefetch" href="/assets/index.html-005dcef4.js" as="script"><link rel="prefetch" href="/assets/index.html-cb60177c.js" as="script"><link rel="prefetch" href="/assets/index.html-4ebc5046.js" as="script"><link rel="prefetch" href="/assets/index.html-4f24b19d.js" as="script"><link rel="prefetch" href="/assets/index.html-dfbba271.js" as="script"><link rel="prefetch" href="/assets/index.html-28a746cc.js" as="script"><link rel="prefetch" href="/assets/index.html-665779fd.js" as="script"><link rel="prefetch" href="/assets/index.html-2ceb269f.js" as="script"><link rel="prefetch" href="/assets/index.html-6a19db7b.js" as="script"><link rel="prefetch" href="/assets/index.html-4c31b34a.js" as="script"><link rel="prefetch" href="/assets/index.html-3a5471bb.js" as="script"><link rel="prefetch" href="/assets/index.html-fbec7aca.js" as="script"><link rel="prefetch" href="/assets/index.html-12a1433c.js" as="script"><link rel="prefetch" href="/assets/index.html-a6afdfd8.js" as="script"><link rel="prefetch" href="/assets/index.html-7e969708.js" as="script"><link rel="prefetch" href="/assets/index.html-8641f28b.js" as="script"><link rel="prefetch" href="/assets/index.html-4679ce1f.js" as="script"><link rel="prefetch" href="/assets/index.html-9928b19e.js" as="script"><link rel="prefetch" href="/assets/index.html-a593ac7f.js" as="script"><link rel="prefetch" href="/assets/index.html-5889ccca.js" as="script"><link rel="prefetch" href="/assets/index.html-f701e4d1.js" as="script"><link rel="prefetch" href="/assets/blog.html-61932911.js" as="script"><link rel="prefetch" href="/assets/home.html-dbc6efde.js" as="script"><link rel="prefetch" href="/assets/bzhan-10wan.html-207b37a8.js" as="script"><link rel="prefetch" href="/assets/csdn-1000wan.html-5fae704f.js" as="script"><link rel="prefetch" href="/assets/index.html-926856cb.js" as="script"><link rel="prefetch" href="/assets/zhihu-1000wan.html-ab1664ec.js" as="script"><link rel="prefetch" href="/assets/array.html-4b5a76fb.js" as="script"><link rel="prefetch" href="/assets/double-array.html-5ab66f24.js" as="script"><link rel="prefetch" href="/assets/print.html-7f5b8675.js" as="script"><link rel="prefetch" href="/assets/basic-data-type.html-622a3e1b.js" as="script"><link rel="prefetch" href="/assets/basic-exercise.html-1f24d5d7.js" as="script"><link rel="prefetch" href="/assets/bigdecimal-biginteger.html-505b7626.js" as="script"><link rel="prefetch" href="/assets/flow-control.html-d67b5edb.js" as="script"><link rel="prefetch" href="/assets/javadoc.html-a1fa8fed.js" as="script"><link rel="prefetch" href="/assets/operator.html-d6ab9b89.js" as="script"><link rel="prefetch" href="/assets/type-cast.html-a23855e7.js" as="script"><link rel="prefetch" href="/assets/48-keywords.html-b7599a95.js" as="script"><link rel="prefetch" href="/assets/Overriding.html-17ba525c.js" as="script"><link rel="prefetch" href="/assets/annotation.html-19333c67.js" as="script"><link rel="prefetch" href="/assets/box.html-01c274d8.js" as="script"><link rel="prefetch" href="/assets/class-object.html-f57be11c.js" as="script"><link rel="prefetch" href="/assets/comparable-omparator.html-9ecb0a29.js" as="script"><link rel="prefetch" href="/assets/deep-copy.html-f9fc4421.js" as="script"><link rel="prefetch" href="/assets/enum.html-5e403f4d.js" as="script"><link rel="prefetch" href="/assets/fanshe.html-d07519b8.js" as="script"><link rel="prefetch" href="/assets/generic.html-581837dc.js" as="script"><link rel="prefetch" href="/assets/hashcode.html-082bb1e8.js" as="script"><link rel="prefetch" href="/assets/immutable.html-8f4e8765.js" as="script"><link rel="prefetch" href="/assets/instanceof-jvm.html-4f6a2b64.js" as="script"><link rel="prefetch" href="/assets/instanceof.html-2b2af03c.js" as="script"><link rel="prefetch" href="/assets/int-cache.html-d711fd3d.js" as="script"><link rel="prefetch" href="/assets/java-naming.html-78c19dfa.js" as="script"><link rel="prefetch" href="/assets/java-unicode.html-108e8c99.js" as="script"><link rel="prefetch" href="/assets/jdk-while-for-wuxian-xunhuan.html-232b28dd.js" as="script"><link rel="prefetch" href="/assets/jdk9-char-byte-string.html-466cdc57.js" as="script"><link rel="prefetch" href="/assets/override-overload.html-b8029790.js" as="script"><link rel="prefetch" href="/assets/pass-by-value.html-1286d60a.js" as="script"><link rel="prefetch" href="/assets/true-generic.html-e9fb865e.js" as="script"><link rel="prefetch" href="/assets/varables.html-7a847999.js" as="script"><link rel="prefetch" href="/assets/beijing.html-38abba30.js" as="script"><link rel="prefetch" href="/assets/chengdu.html-0a2a976b.js" as="script"><link rel="prefetch" href="/assets/guangzhou.html-f8bcfecd.js" as="script"><link rel="prefetch" href="/assets/hangzhou.html-4fac9f96.js" as="script"><link rel="prefetch" href="/assets/jinan.html-68950a32.js" as="script"><link rel="prefetch" href="/assets/nanjing.html-191777a0.js" as="script"><link rel="prefetch" href="/assets/qingdao.html-94dfc6e0.js" as="script"><link rel="prefetch" href="/assets/shenzhen.html-d65ea7c6.js" as="script"><link rel="prefetch" href="/assets/suzhou.html-7853fd76.js" as="script"><link rel="prefetch" href="/assets/wuhan.html-285b6b4e.js" as="script"><link rel="prefetch" href="/assets/xian.html-0c918d48.js" as="script"><link rel="prefetch" href="/assets/zhengzhou.html-f85619a8.js" as="script"><link rel="prefetch" href="/assets/PriorityQueue.html-c108274b.js" as="script"><link rel="prefetch" href="/assets/WeakHashMap.html-3adb9507.js" as="script"><link rel="prefetch" href="/assets/arraydeque.html-91482594.js" as="script"><link rel="prefetch" href="/assets/arraylist.html-62d370e8.js" as="script"><link rel="prefetch" href="/assets/fail-fast.html-dbf283e6.js" as="script"><link rel="prefetch" href="/assets/gailan.html-869c181a.js" as="script"><link rel="prefetch" href="/assets/hashmap.html-2ae1a414.js" as="script"><link rel="prefetch" href="/assets/iterator-iterable.html-c54bc4c9.js" as="script"><link rel="prefetch" href="/assets/linkedhashmap.html-caa46690.js" as="script"><link rel="prefetch" href="/assets/linkedlist.html-0594f850.js" as="script"><link rel="prefetch" href="/assets/list-war-2.html-5da378cf.js" as="script"><link rel="prefetch" href="/assets/time-complexity.html-b93cb9f0.js" as="script"><link rel="prefetch" href="/assets/treemap.html-1d5b8556.js" as="script"><link rel="prefetch" href="/assets/Objects.html-b625544e.js" as="script"><link rel="prefetch" href="/assets/StringUtils.html-59bd1d8a.js" as="script"><link rel="prefetch" href="/assets/arrays.html-a45f5617.js" as="script"><link rel="prefetch" href="/assets/collections.html-9668d354.js" as="script"><link rel="prefetch" href="/assets/guava.html-4533d654.js" as="script"><link rel="prefetch" href="/assets/hutool.html-1636cf58.js" as="script"><link rel="prefetch" href="/assets/scanner.html-9b6946db.js" as="script"><link rel="prefetch" href="/assets/utils.html-7041f39d.js" as="script"><link rel="prefetch" href="/assets/os.html-aee33541.js" as="script"><link rel="prefetch" href="/assets/wangluo.html-2fa87136.js" as="script"><link rel="prefetch" href="/assets/history.html-8f437b01.js" as="script"><link rel="prefetch" href="/assets/javabooks.html-6339135a.js" as="script"><link rel="prefetch" href="/assets/learn-jianyi.html-e7b30312.js" as="script"><link rel="prefetch" href="/assets/nicearticle.html-496e581b.js" as="script"><link rel="prefetch" href="/assets/rumen.html-da046574.js" as="script"><link rel="prefetch" href="/assets/gailan.html-83bb91a1.js" as="script"><link rel="prefetch" href="/assets/npe.html-09cdb6ec.js" as="script"><link rel="prefetch" href="/assets/shijian.html-9cd76046.js" as="script"><link rel="prefetch" href="/assets/try-catch-xingneng.html-6bf702d5.js" as="script"><link rel="prefetch" href="/assets/try-with-resources.html-250cc37f.js" as="script"><link rel="prefetch" href="/assets/git-qiyuan.html-3381d139.js" as="script"><link rel="prefetch" href="/assets/progit.html-6c610324.js" as="script"><link rel="prefetch" href="/assets/DBeaver.html-c2f0a140.js" as="script"><link rel="prefetch" href="/assets/brew.html-d8622230.js" as="script"><link rel="prefetch" href="/assets/chiner.html-10d8a95d.js" as="script"><link rel="prefetch" href="/assets/choco.html-11705b9e.js" as="script"><link rel="prefetch" href="/assets/fastjson.html-b93a0fdc.js" as="script"><link rel="prefetch" href="/assets/forest.html-1426f82a.js" as="script"><link rel="prefetch" href="/assets/gson.html-0d2c65b9.js" as="script"><link rel="prefetch" href="/assets/jackson.html-1aa47ad1.js" as="script"><link rel="prefetch" href="/assets/junit.html-279268c9.js" as="script"><link rel="prefetch" href="/assets/knife4j.html-13c41d96.js" as="script"><link rel="prefetch" href="/assets/log4j.html-ae990373.js" as="script"><link rel="prefetch" href="/assets/log4j2.html-0350f28e.js" as="script"><link rel="prefetch" href="/assets/logback.html-a4f76b8e.js" as="script"><link rel="prefetch" href="/assets/others.html-a3f7843b.js" as="script"><link rel="prefetch" href="/assets/slf4j.html-7a945f76.js" as="script"><link rel="prefetch" href="/assets/tabby.html-36f0ef5b.js" as="script"><link rel="prefetch" href="/assets/warp.html-3435635e.js" as="script"><link rel="prefetch" href="/assets/windterm.html-0cb1396a.js" as="script"><link rel="prefetch" href="/assets/4-debug-skill.html-e15d9a82.js" as="script"><link rel="prefetch" href="/assets/shenji-chajian-10.html-c2119387.js" as="script"><link rel="prefetch" href="/assets/xechat.html-8af6c7ec.js" as="script"><link rel="prefetch" href="/assets/dubbo-17.html-0ec9bcc2.js" as="script"><link rel="prefetch" href="/assets/java-34.html-2ca81a0d.js" as="script"><link rel="prefetch" href="/assets/java-basic-baguwen.html-52c1067f.js" as="script"><link rel="prefetch" href="/assets/java-hashmap-13.html-23f9ef2b.js" as="script"><link rel="prefetch" href="/assets/java-jvm-baguwen.html-20252ac0.js" as="script"><link rel="prefetch" href="/assets/java-thread-baguwen.html-3042b4fa.js" as="script"><link rel="prefetch" href="/assets/kafka-40.html-aaef16f2.js" as="script"><link rel="prefetch" href="/assets/mianshiguan-bigfile-miaochuan.html-78a151c7.js" as="script"><link rel="prefetch" href="/assets/mianshiguan-fenkufenbiao.html-be1d0f32.js" as="script"><link rel="prefetch" href="/assets/mianshiguan-youhuiquan.html-84b1950d.js" as="script"><link rel="prefetch" href="/assets/mysql-60.html-5c3c1e8e.js" as="script"><link rel="prefetch" href="/assets/mysql-suoyin-15.html-64963f9f.js" as="script"><link rel="prefetch" href="/assets/nginx-40.html-8a284624.js" as="script"><link rel="prefetch" href="/assets/redis-12.html-e452b67a.js" as="script"><link rel="prefetch" href="/assets/Serializbale.html-d28dc85a.js" as="script"><link rel="prefetch" href="/assets/buffer.html-730864bc.js" as="script"><link rel="prefetch" href="/assets/char-byte.html-0f6cf841.js" as="script"><link rel="prefetch" href="/assets/file-path.html-ce99a528.js" as="script"><link rel="prefetch" href="/assets/print.html-da1239d6.js" as="script"><link rel="prefetch" href="/assets/reader-writer.html-fc6cd577.js" as="script"><link rel="prefetch" href="/assets/serialize.html-9e323284.js" as="script"><link rel="prefetch" href="/assets/shangtou.html-896bf38f.js" as="script"><link rel="prefetch" href="/assets/stream.html-487f5240.js" as="script"><link rel="prefetch" href="/assets/transient.html-4c226ace.js" as="script"><link rel="prefetch" href="/assets/Lambda.html-f8ffb6cf.js" as="script"><link rel="prefetch" href="/assets/java14.html-a9f82df9.js" as="script"><link rel="prefetch" href="/assets/optional.html-9b0ab081.js" as="script"><link rel="prefetch" href="/assets/stream.html-f84755a9.js" as="script"><link rel="prefetch" href="/assets/asm.html-a27b4d17.js" as="script"><link rel="prefetch" href="/assets/bytecode.html-509be837.js" as="script"><link rel="prefetch" href="/assets/class-file-jiegou.html-a6c362d6.js" as="script"><link rel="prefetch" href="/assets/class-load.html-979073ad.js" as="script"><link rel="prefetch" href="/assets/compile-jdk.html-90b74b68.js" as="script"><link rel="prefetch" href="/assets/cpu-percent-100.html-06a45b36.js" as="script"><link rel="prefetch" href="/assets/garbage-collector.html-b6ade488.js" as="script"><link rel="prefetch" href="/assets/gc-collector.html-e1c7c730.js" as="script"><link rel="prefetch" href="/assets/gc.html-f5bdbb53.js" as="script"><link rel="prefetch" href="/assets/how-jvm-run-zijiema-zhiling.html-aa3f999c.js" as="script"><link rel="prefetch" href="/assets/how-run-java-code.html-fa670d43.js" as="script"><link rel="prefetch" href="/assets/hsdb.html-a59f7dd8.js" as="script"><link rel="prefetch" href="/assets/jit.html-e87949bc.js" as="script"><link rel="prefetch" href="/assets/meituan-9-gc.html-fcd52718.js" as="script"><link rel="prefetch" href="/assets/neicun-jiegou.html-21032579.js" as="script"><link rel="prefetch" href="/assets/oom.html-b16bb1f4.js" as="script"><link rel="prefetch" href="/assets/problem-tools.html-9a065329.js" as="script"><link rel="prefetch" href="/assets/index.html-cefc25e8.js" as="script"><link rel="prefetch" href="/assets/stack-frame.html-101da16c.js" as="script"><link rel="prefetch" href="/assets/tujie-gc.html-dfceda31.js" as="script"><link rel="prefetch" href="/assets/vm-stack-register.html-5184719f.js" as="script"><link rel="prefetch" href="/assets/what-happen-when-javac.html-7555b559.js" as="script"><link rel="prefetch" href="/assets/what-is-jvm.html-45dac997.js" as="script"><link rel="prefetch" href="/assets/whereis-the-object.html-d5a65b84.js" as="script"><link rel="prefetch" href="/assets/zijiema-zhiling.html-458e670b.js" as="script"><link rel="prefetch" href="/assets/zongjie.html-9d344848.js" as="script"><link rel="prefetch" href="/assets/auto-generator.html-0b548f6e.js" as="script"><link rel="prefetch" href="/assets/index.html-f9f58bef.js" as="script"><link rel="prefetch" href="/assets/yuneban-wangyiyunyinyue.html-33d6ae2b.js" as="script"><link rel="prefetch" href="/assets/maven.html-a63902cb.js" as="script"><link rel="prefetch" href="/assets/chengxyspnhxagzl.html-a1641c8d.js" as="script"><link rel="prefetch" href="/assets/huanxgzl.html-c3e4703d.js" as="script"><link rel="prefetch" href="/assets/quzjlsspdx.html-c8c71f39.js" as="script"><link rel="prefetch" href="/assets/shanganaliyun.html-d4d92628.js" as="script"><link rel="prefetch" href="/assets/shezynmjfxhelmtttjddd.html-19a0f3a5.js" as="script"><link rel="prefetch" href="/assets/xuelybdzheloffer.html-a20fb75c.js" as="script"><link rel="prefetch" href="/assets/zheisnylzldhzd.html-8f0d5192.js" as="script"><link rel="prefetch" href="/assets/api-wangguan.html-73d2b4a4.js" as="script"><link rel="prefetch" href="/assets/rumen.html-cb29da1a.js" as="script"><link rel="prefetch" href="/assets/100-budiushi.html-ca66a040.js" as="script"><link rel="prefetch" href="/assets/kafka.html-89e75776.js" as="script"><link rel="prefetch" href="/assets/rabbitmq-rumen.html-0494ef50.js" as="script"><link rel="prefetch" href="/assets/install.html-ab468e25.js" as="script"><link rel="prefetch" href="/assets/lijie-shiwu.html-c7d9a583.js" as="script"><link rel="prefetch" href="/assets/redis-shuju-yizhixing.html-06e46a68.js" as="script"><link rel="prefetch" href="/assets/shiwu-shixian.html-cc810518.js" as="script"><link rel="prefetch" href="/assets/rumen.html-6ad9d71c.js" as="script"><link rel="prefetch" href="/assets/nginx.html-4465f299.js" as="script"><link rel="prefetch" href="/assets/BIONIOAIO.html-d34b1c25.js" as="script"><link rel="prefetch" href="/assets/buffer-channel.html-b33aad49.js" as="script"><link rel="prefetch" href="/assets/moxing.html-35745e5b.js" as="script"><link rel="prefetch" href="/assets/network-connect.html-cb0c5230.js" as="script"><link rel="prefetch" href="/assets/nio-better-io.html-1d3fd99d.js" as="script"><link rel="prefetch" href="/assets/paths-files.html-1934f88e.js" as="script"><link rel="prefetch" href="/assets/abstract-vs-interface.html-2550a9ff.js" as="script"><link rel="prefetch" href="/assets/abstract.html-dc7556e2.js" as="script"><link rel="prefetch" href="/assets/access-control.html-db229764.js" as="script"><link rel="prefetch" href="/assets/code-init.html-4c6bd9f6.js" as="script"><link rel="prefetch" href="/assets/construct.html-5cf3b652.js" as="script"><link rel="prefetch" href="/assets/encapsulation-inheritance-polymorphism.html-d9c611c6.js" as="script"><link rel="prefetch" href="/assets/encapsulation.html-cfeccb1f.js" as="script"><link rel="prefetch" href="/assets/extends-bigsai.html-c73ffc93.js" as="script"><link rel="prefetch" href="/assets/final.html-551d9306.js" as="script"><link rel="prefetch" href="/assets/inner-class.html-53a6e848.js" as="script"><link rel="prefetch" href="/assets/interface.html-7fd97fa9.js" as="script"><link rel="prefetch" href="/assets/method.html-47751aa8.js" as="script"><link rel="prefetch" href="/assets/native-method.html-b1cd9ad2.js" as="script"><link rel="prefetch" href="/assets/object-class.html-e92bb37f.js" as="script"><link rel="prefetch" href="/assets/package.html-554a9c5f.js" as="script"><link rel="prefetch" href="/assets/polymorphism.html-36d25db0.js" as="script"><link rel="prefetch" href="/assets/static.html-ee7e5579.js" as="script"><link rel="prefetch" href="/assets/this-super.html-837bd57c.js" as="script"><link rel="prefetch" href="/assets/var.html-85c2a8c5.js" as="script"><link rel="prefetch" href="/assets/IDEA-install-config.html-3b55c643.js" as="script"><link rel="prefetch" href="/assets/hello-world.html-f7f17d28.js" as="script"><link rel="prefetch" href="/assets/java-can-do-what.html-6ef99c3b.js" as="script"><link rel="prefetch" href="/assets/java-history.html-ca3d588a.js" as="script"><link rel="prefetch" href="/assets/jdk-install-config.html-06ed450c.js" as="script"><link rel="prefetch" href="/assets/index.html-27245dee.js" as="script"><link rel="prefetch" href="/assets/what-is-java.html-9192d343.js" as="script"><link rel="prefetch" href="/assets/ali-java-shouce.html-68acf06a.js" as="script"><link rel="prefetch" href="/assets/bat-shuati.html-dde90da6.js" as="script"><link rel="prefetch" href="/assets/github-java-jiaocheng-115-star.html-62f3dbea.js" as="script"><link rel="prefetch" href="/assets/java-concurrent.html-d860912f.js" as="script"><link rel="prefetch" href="/assets/java-leetcode.html-02fa10a3.js" as="script"><link rel="prefetch" href="/assets/java.html-fbcbaf70.js" as="script"><link rel="prefetch" href="/assets/jianli.html-c5089148.js" as="script"><link rel="prefetch" href="/assets/os.html-9aade61d.js" as="script"><link rel="prefetch" href="/assets/progit.html-142f7bdc.js" as="script"><link rel="prefetch" href="/assets/programmer-111.html-788937b1.js" as="script"><link rel="prefetch" href="/assets/index.html-e544b19c.js" as="script"><link rel="prefetch" href="/assets/shejimoshi.html-0a160e90.js" as="script"><link rel="prefetch" href="/assets/yuanyifeng-c-language.html-40810d87.js" as="script"><link rel="prefetch" href="/assets/install.html-aaa885c2.js" as="script"><link rel="prefetch" href="/assets/redis-springboot.html-7025d0ad.js" as="script"><link rel="prefetch" href="/assets/rumen.html-f35f48ff.js" as="script"><link rel="prefetch" href="/assets/xuebeng-chuantou-jichuan.html-94807cb9.js" as="script"><link rel="prefetch" href="/assets/computer-base.html-7159fb4b.js" as="script"><link rel="prefetch" href="/assets/http.html-9ca9a687.js" as="script"><link rel="prefetch" href="/assets/network-base.html-46729e10.js" as="script"><link rel="prefetch" href="/assets/socket.html-40f1e464.js" as="script"><link rel="prefetch" href="/assets/Filter-Interceptor-Listener.html-76ffed9e.js" as="script"><link rel="prefetch" href="/assets/aop-log.html-5d003047.js" as="script"><link rel="prefetch" href="/assets/cors.html-a3465572.js" as="script"><link rel="prefetch" href="/assets/docker.html-79627aba.js" as="script"><link rel="prefetch" href="/assets/initializr.html-1122fd7b.js" as="script"><link rel="prefetch" href="/assets/ioc.html-c6c81028.js" as="script"><link rel="prefetch" href="/assets/jpa.html-556bea95.js" as="script"><link rel="prefetch" href="/assets/jwt.html-46eb8083.js" as="script"><link rel="prefetch" href="/assets/linux-codingmore-run.html-28fce41d.js" as="script"><link rel="prefetch" href="/assets/logback.html-439e0723.js" as="script"><link rel="prefetch" href="/assets/lombok.html-27e7923d.js" as="script"><link rel="prefetch" href="/assets/macos-codingmore-run.html-89b968cc.js" as="script"><link rel="prefetch" href="/assets/mybatis.html-0e0aa322.js" as="script"><link rel="prefetch" href="/assets/mysql-druid.html-8e7c7bf9.js" as="script"><link rel="prefetch" href="/assets/oss.html-7f89b95e.js" as="script"><link rel="prefetch" href="/assets/quartz.html-88f290d3.js" as="script"><link rel="prefetch" href="/assets/springtask.html-80574486.js" as="script"><link rel="prefetch" href="/assets/swagger.html-43f1aa4a.js" as="script"><link rel="prefetch" href="/assets/thymeleaf.html-347ed227.js" as="script"><link rel="prefetch" href="/assets/tomcat.html-6aabcb46.js" as="script"><link rel="prefetch" href="/assets/transaction.html-16bd5d75.js" as="script"><link rel="prefetch" href="/assets/validator.html-69224155.js" as="script"><link rel="prefetch" href="/assets/windows-codingmore-run.html-11305f05.js" as="script"><link rel="prefetch" href="/assets/builder-buffer.html-978126df.js" as="script"><link rel="prefetch" href="/assets/constant-pool.html-738dca52.js" as="script"><link rel="prefetch" href="/assets/equals.html-9d050675.js" as="script"><link rel="prefetch" href="/assets/immutable.html-73215224.js" as="script"><link rel="prefetch" href="/assets/intern.html-e4dba897.js" as="script"><link rel="prefetch" href="/assets/join.html-23544566.js" as="script"><link rel="prefetch" href="/assets/split.html-7d15004a.js" as="script"><link rel="prefetch" href="/assets/string-source.html-30fca56d.js" as="script"><link rel="prefetch" href="/assets/buy-cloud-server.html-a5496c2f.js" as="script"><link rel="prefetch" href="/assets/buy-domain.html-bcc0391b.js" as="script"><link rel="prefetch" href="/assets/https-domain.html-eee0afb6.js" as="script"><link rel="prefetch" href="/assets/install-baota-mianban.html-74b4be16.js" as="script"><link rel="prefetch" href="/assets/record-domain.html-8936176f.js" as="script"><link rel="prefetch" href="/assets/tobebetterjavaer-wangzhan-shangxian.html-c3077ac6.js" as="script"><link rel="prefetch" href="/assets/tupian-zhuanlian.html-42a59b11.js" as="script"><link rel="prefetch" href="/assets/BlockingQueue.html-b0c034d2.js" as="script"><link rel="prefetch" href="/assets/ConcurrentHashMap.html-9001ea8c.js" as="script"><link rel="prefetch" href="/assets/ConcurrentLinkedQueue.html-c07a5745.js" as="script"><link rel="prefetch" href="/assets/CopyOnWriteArrayList.html-b42d8252.js" as="script"><link rel="prefetch" href="/assets/CountDownLatch.html-7cfa05ec.js" as="script"><link rel="prefetch" href="/assets/LockSupport.html-a1d2eb45.js" as="script"><link rel="prefetch" href="/assets/ReentrantReadWriteLock.html-44e17940.js" as="script"><link rel="prefetch" href="/assets/ScheduledThreadPoolExecutor.html-a64f081f.js" as="script"><link rel="prefetch" href="/assets/ThreadLocal.html-87007e54.js" as="script"><link rel="prefetch" href="/assets/Unsafe.html-2c1b31a8.js" as="script"><link rel="prefetch" href="/assets/ali-executors.html-cb2f0e37.js" as="script"><link rel="prefetch" href="/assets/aqs.html-7888738b.js" as="script"><link rel="prefetch" href="/assets/atomic.html-03949ff4.js" as="script"><link rel="prefetch" href="/assets/callable-future-futuretask.html-69f2101a.js" as="script"><link rel="prefetch" href="/assets/cas.html-d6ff9288.js" as="script"><link rel="prefetch" href="/assets/condition.html-32b687eb.js" as="script"><link rel="prefetch" href="/assets/fork-join.html-4b2098bf.js" as="script"><link rel="prefetch" href="/assets/jmm.html-b7b68ca4.js" as="script"><link rel="prefetch" href="/assets/lock.html-a4fe2e03.js" as="script"><link rel="prefetch" href="/assets/map.html-1fd99959.js" as="script"><link rel="prefetch" href="/assets/pianxiangsuo.html-bbcfa014.js" as="script"><link rel="prefetch" href="/assets/pool.html-69d034b3.js" as="script"><link rel="prefetch" href="/assets/index.html-6264830a.js" as="script"><link rel="prefetch" href="/assets/reentrantLock.html-f874ce11.js" as="script"><link rel="prefetch" href="/assets/shengchanzhe-xiaofeizhe.html-94f4eb13.js" as="script"><link rel="prefetch" href="/assets/suo.html-c15d28ca.js" as="script"><link rel="prefetch" href="/assets/synchronized-1.html-facafa55.js" as="script"><link rel="prefetch" href="/assets/synchronized.html-5017e01c.js" as="script"><link rel="prefetch" href="/assets/thread-bring-some-problem.html-dc72ddac.js" as="script"><link rel="prefetch" href="/assets/thread-group-and-thread-priority.html-d322495b.js" as="script"><link rel="prefetch" href="/assets/thread-state-and-method.html-34d9c4b9.js" as="script"><link rel="prefetch" href="/assets/volatile.html-5db2f6ad.js" as="script"><link rel="prefetch" href="/assets/wangzhe-thread.html-ab0de543.js" as="script"><link rel="prefetch" href="/assets/why-need-thread.html-8785a679.js" as="script"><link rel="prefetch" href="/assets/aliyun-shuaiguo-gongchengshi.html-fd990404.js" as="script"><link rel="prefetch" href="/assets/chadiansanhuo.html-35f383f7.js" as="script"><link rel="prefetch" href="/assets/chengxuyuannv-chonghui-java.html-277eb75d.js" as="script"><link rel="prefetch" href="/assets/daxue-nuli-jisuanji.html-4777944b.js" as="script"><link rel="prefetch" href="/assets/fumutuanju.html-83da5e5c.js" as="script"><link rel="prefetch" href="/assets/20ren-it-quma.html-ef877692.js" as="script"><link rel="prefetch" href="/assets/35-weiji.html-fca9d231.js" as="script"><link rel="prefetch" href="/assets/408.html-72f0e6c0.js" as="script"><link rel="prefetch" href="/assets/LearnCS-ByYourself.html-d330ed76.js" as="script"><link rel="prefetch" href="/assets/benkesheng-ali-tengxun.html-a86228c1.js" as="script"><link rel="prefetch" href="/assets/chengxuyuan-fuye.html-59203051.js" as="script"><link rel="prefetch" href="/assets/electron-information-engineering.html-9e6ae335.js" as="script"><link rel="prefetch" href="/assets/gaobingfa-jingyan-hsmcomputer.html-fdc60aa0.js" as="script"><link rel="prefetch" href="/assets/gaokao-zhiyuan-cs.html-a63b5ee9.js" as="script"><link rel="prefetch" href="/assets/hr-xinzi.html-d0179ee6.js" as="script"><link rel="prefetch" href="/assets/read-csapp.html-99b6cb59.js" as="script"><link rel="prefetch" href="/assets/ruhzfzdgzzcxcz.html-2213a27e.js" as="script"><link rel="prefetch" href="/assets/test-programmer-read-books.html-496c0ae3.js" as="script"><link rel="prefetch" href="/assets/xiaozhao-java-should-master.html-c8a34cda.js" as="script"><link rel="prefetch" href="/assets/algorithm.html-eaaeb63c.js" as="script"><link rel="prefetch" href="/assets/android.html-fe91a5cb.js" as="script"><link rel="prefetch" href="/assets/bigdata.html-e5672d2e.js" as="script"><link rel="prefetch" href="/assets/c.html-4af9de03.js" as="script"><link rel="prefetch" href="/assets/ccc.html-5fcf809c.js" as="script"><link rel="prefetch" href="/assets/donet.html-076a2aad.js" as="script"><link rel="prefetch" href="/assets/go.html-26cb2c50.js" as="script"><link rel="prefetch" href="/assets/lanqiaobei.html-09ed791f.js" as="script"><link rel="prefetch" href="/assets/mysql.html-f2824026.js" as="script"><link rel="prefetch" href="/assets/os.html-8d5ea793.js" as="script"><link rel="prefetch" href="/assets/python.html-07328db0.js" as="script"><link rel="prefetch" href="/assets/qianduan.html-5c9e3e70.js" as="script"><link rel="prefetch" href="/assets/index.html-5ee5c8ed.js" as="script"><link rel="prefetch" href="/assets/redis.html-eeaf2790.js" as="script"><link rel="prefetch" href="/assets/august.html-fad9d448.js" as="script"><link rel="prefetch" href="/assets/first.html-bbe17ff3.js" as="script"><link rel="prefetch" href="/assets/java-mianshi-zhinan.html-c5596811.js" as="script"><link rel="prefetch" href="/assets/jianli.html-fe93caae.js" as="script"><link rel="prefetch" href="/assets/july.html-a919c8d2.js" as="script"><link rel="prefetch" href="/assets/june.html-6e7eb152.js" as="script"><link rel="prefetch" href="/assets/map.html-1c8a1a21.js" as="script"><link rel="prefetch" href="/assets/may.html-afaf217f.js" as="script"><link rel="prefetch" href="/assets/mianshi.html-7d52ea6e.js" as="script"><link rel="prefetch" href="/assets/paicoding.html-efd0bcac.js" as="script"><link rel="prefetch" href="/assets/index.html-eb6db7aa.js" as="script"><link rel="prefetch" href="/assets/jibenjieshao.html-6e457be9.js" as="script"><link rel="prefetch" href="/assets/luoczbmsddyb.html-8156c2ac.js" as="script"><link rel="prefetch" href="/assets/miansmtgl.html-4f03ca9f.js" as="script"><link rel="prefetch" href="/assets/xzbztdncdlxgljsjq.html-633309d0.js" as="script"><link rel="prefetch" href="/assets/youdxzhhmjzlycfx.html-e218ab35.js" as="script"><link rel="prefetch" href="/assets/zijxjjdyfqzgl.html-c79c6532.js" as="script"><link rel="prefetch" href="/assets/javase.html-ff7fbf04.js" as="script"><link rel="prefetch" href="/assets/collection.html-5f1bbacb.js" as="script"><link rel="prefetch" href="/assets/fenbushi.html-e7acfc48.js" as="script"><link rel="prefetch" href="/assets/javase.html-5c23f91d.js" as="script"><link rel="prefetch" href="/assets/javathread.html-99c9cfb3.js" as="script"><link rel="prefetch" href="/assets/jvm.html-e55c2fc5.js" as="script"><link rel="prefetch" href="/assets/mybatis.html-6a29e269.js" as="script"><link rel="prefetch" href="/assets/mysql.html-0cba0980.js" as="script"><link rel="prefetch" href="/assets/network.html-a6339f49.js" as="script"><link rel="prefetch" href="/assets/nixi.html-06b8e71c.js" as="script"><link rel="prefetch" href="/assets/os.html-76b55d4f.js" as="script"><link rel="prefetch" href="/assets/redis.html-29852abd.js" as="script"><link rel="prefetch" href="/assets/rocketmq.html-7c1365dc.js" as="script"><link rel="prefetch" href="/assets/spring.html-b205f45e.js" as="script"><link rel="prefetch" href="/assets/weifuwu.html-5bf2b60b.js" as="script"><link rel="prefetch" href="/assets/jvm.html-e4c9f341.js" as="script"><link rel="prefetch" href="/assets/thread.html-6c709448.js" as="script"><link rel="prefetch" href="/assets/yitiaolong.html-013cddb4.js" as="script"><link rel="prefetch" href="/assets/404.html-662c4377.js" as="script"><link rel="prefetch" href="/assets/index.html-65f71d35.js" as="script"><link rel="prefetch" href="/assets/index.html-0196820e.js" as="script"><link rel="prefetch" href="/assets/index.html-355d3843.js" as="script"><link rel="prefetch" href="/assets/index.html-88857071.js" as="script"><link rel="prefetch" href="/assets/index.html-8d35750d.js" as="script"><link rel="prefetch" href="/assets/index.html-c9c5534a.js" as="script"><link rel="prefetch" href="/assets/index.html-b700c805.js" as="script"><link rel="prefetch" href="/assets/index.html-3fbef48c.js" as="script"><link rel="prefetch" href="/assets/index.html-5f1804ed.js" as="script"><link rel="prefetch" href="/assets/index.html-052bccee.js" as="script"><link rel="prefetch" href="/assets/index.html-0922476c.js" as="script"><link rel="prefetch" href="/assets/index.html-033e85d5.js" as="script"><link rel="prefetch" href="/assets/index.html-ba418312.js" as="script"><link rel="prefetch" href="/assets/index.html-8d848fa4.js" as="script"><link rel="prefetch" href="/assets/index.html-9aa193cc.js" as="script"><link rel="prefetch" href="/assets/index.html-f2860520.js" as="script"><link rel="prefetch" href="/assets/index.html-a22af14c.js" as="script"><link rel="prefetch" href="/assets/index.html-70f0899c.js" as="script"><link rel="prefetch" href="/assets/index.html-6ddc2bf4.js" as="script"><link rel="prefetch" href="/assets/index.html-b2d8871f.js" as="script"><link rel="prefetch" href="/assets/index.html-4f12724c.js" as="script"><link rel="prefetch" href="/assets/index.html-fdbaa207.js" as="script"><link rel="prefetch" href="/assets/index.html-2c243d7f.js" as="script"><link rel="prefetch" href="/assets/index.html-543a1d87.js" as="script"><link rel="prefetch" href="/assets/index.html-3d26b925.js" as="script"><link rel="prefetch" href="/assets/index.html-15a2013e.js" as="script"><link rel="prefetch" href="/assets/index.html-b12fdc3c.js" as="script"><link rel="prefetch" href="/assets/index.html-ef76fa15.js" as="script"><link rel="prefetch" href="/assets/index.html-16fda3de.js" as="script"><link rel="prefetch" href="/assets/index.html-189c140a.js" as="script"><link rel="prefetch" href="/assets/index.html-c3b365c8.js" as="script"><link rel="prefetch" href="/assets/index.html-006fab13.js" as="script"><link rel="prefetch" href="/assets/index.html-da27d44d.js" as="script"><link rel="prefetch" href="/assets/index.html-0fc2c9a7.js" as="script"><link rel="prefetch" href="/assets/index.html-ebb2e101.js" as="script"><link rel="prefetch" href="/assets/index.html-7195e729.js" as="script"><link rel="prefetch" href="/assets/index.html-bb50be3c.js" as="script"><link rel="prefetch" href="/assets/index.html-44eca8aa.js" as="script"><link rel="prefetch" href="/assets/index.html-4e58c96a.js" as="script"><link rel="prefetch" href="/assets/index.html-c7ffcf0f.js" as="script"><link rel="prefetch" href="/assets/mermaid.core-39b03a6a.js" as="script"><link rel="prefetch" href="/assets/markdown.esm-abe06b83.js" as="script"><link rel="prefetch" href="/assets/reveal.esm-ec5549c1.js" as="script"><link rel="prefetch" href="/assets/photoswipe.esm-4e1eea98.js" as="script"><link rel="prefetch" href="/assets/index-e32a7948.js" as="script"><link rel="prefetch" href="/assets/giscus-0b7adcf8.js" as="script"><link rel="prefetch" href="/assets/style-e9220a04.js" as="script"><link rel="prefetch" href="/assets/docsearch-1d421ddb.js" as="script"><link rel="prefetch" href="/assets/index-82585c84.js" as="script">
</head>
<body>
<div id="app"><!--[--><!--[--><!--[--><span tabindex="-1"></span><a href="#main-content" class="vp-skip-link sr-only">跳至主要內容</a><!--]--><div class="theme-container has-toc"><!--[--><header id="navbar" class="vp-navbar"><div class="vp-navbar-start"><button type="button" class="vp-toggle-sidebar-button" title="Toggle Sidebar"><span class="icon"></span></button><!--[--><!----><!--]--><!--[--><a class="vp-link vp-brand" href="/"><img class="vp-nav-logo" src="https://cdn.tobebetterjavaer.com/tobebetterjavaer/images/logo-02.png" alt="二哥的Java进阶之路"><!----><span class="vp-site-name hide-in-pad">二哥的Java进阶之路</span></a><!--]--><!--[--><!----><!--]--></div><div class="vp-navbar-center"><!--[--><!----><!--]--><!--[--><nav class="vp-nav-links"><div class="nav-item hide-in-mobile"><a class="vp-link nav-link" href="/blog.html"><span class="font-icon icon iconfont icon-gaishu" style=""></span>博客<!----></a></div><div class="nav-item hide-in-mobile"><a class="vp-link nav-link" href="/home.html"><span class="font-icon icon iconfont icon-lujing" style=""></span>进阶之路<!----></a></div><div class="nav-item hide-in-mobile"><a class="vp-link nav-link" href="/zhishixingqiu/"><span class="font-icon icon iconfont icon-Artboard" style=""></span>知识星球<!----></a></div><div class="nav-item hide-in-mobile"><a class="vp-link nav-link" href="/xuexiluxian/"><span class="font-icon icon iconfont icon-luxian" style=""></span>学习路线<!----></a></div><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button type="button" class="dropdown-title" aria-label="珍藏资源"><span class="title"><span class="font-icon icon iconfont icon-youzhi" style=""></span>珍藏资源</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a class="vp-link nav-link" href="/pdf/"><span class="font-icon icon iconfont icon-java" style=""></span>PDF下载<!----></a></li><li class="dropdown-item"><a class="vp-link nav-link" href="/sidebar/sanfene/nixi.html"><span class="font-icon icon iconfont icon-zhunbei" style=""></span>面渣逆袭<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><a href="https://space.bilibili.com/513340480" rel="noopener noreferrer" target="_blank" aria-label="B站视频" class="nav-link"><span class="font-icon icon iconfont icon-bzhan" style=""></span>B站视频<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div></nav><!--]--><!--[--><!----><!--]--></div><div class="vp-navbar-end"><!--[--><!----><!--]--><!--[--><!----><div class="nav-item vp-repo"><a class="vp-repo-link" href="https://github.com/itwanger/toBeBetterJavaer" target="_blank" rel="noopener noreferrer" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" class="icon github-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="github icon" style="width:1.25rem;height:1.25rem;vertical-align:middle;"><path d="M511.957 21.333C241.024 21.333 21.333 240.981 21.333 512c0 216.832 140.544 400.725 335.574 465.664 24.49 4.395 32.256-10.07 32.256-23.083 0-11.69.256-44.245 0-85.205-136.448 29.61-164.736-64.64-164.736-64.64-22.315-56.704-54.4-71.765-54.4-71.765-44.587-30.464 3.285-29.824 3.285-29.824 49.195 3.413 75.179 50.517 75.179 50.517 43.776 75.008 114.816 53.333 142.762 40.79 4.523-31.66 17.152-53.377 31.19-65.537-108.971-12.458-223.488-54.485-223.488-242.602 0-53.547 19.114-97.323 50.517-131.67-5.035-12.33-21.93-62.293 4.779-129.834 0 0 41.258-13.184 134.912 50.346a469.803 469.803 0 0 1 122.88-16.554c41.642.213 83.626 5.632 122.88 16.554 93.653-63.488 134.784-50.346 134.784-50.346 26.752 67.541 9.898 117.504 4.864 129.834 31.402 34.347 50.474 78.123 50.474 131.67 0 188.586-114.73 230.016-224.042 242.09 17.578 15.232 33.578 44.672 33.578 90.454v135.85c0 13.142 7.936 27.606 32.854 22.87C862.25 912.597 1002.667 728.747 1002.667 512c0-271.019-219.648-490.667-490.71-490.667z"></path></svg></a></div><div class="nav-item hide-in-mobile"><button type="button" class="outlook-button" tabindex="-1" aria-hidden="true"><svg xmlns="http://www.w3.org/2000/svg" class="icon outlook-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="outlook icon"><path d="M224 800c0 9.6 3.2 44.8 6.4 54.4 6.4 48-48 76.8-48 76.8s80 41.6 147.2 0 134.4-134.4 38.4-195.2c-22.4-12.8-41.6-19.2-57.6-19.2C259.2 716.8 227.2 761.6 224 800zM560 675.2l-32 51.2c-51.2 51.2-83.2 32-83.2 32 25.6 67.2 0 112-12.8 128 25.6 6.4 51.2 9.6 80 9.6 54.4 0 102.4-9.6 150.4-32l0 0c3.2 0 3.2-3.2 3.2-3.2 22.4-16 12.8-35.2 6.4-44.8-9.6-12.8-12.8-25.6-12.8-41.6 0-54.4 60.8-99.2 137.6-99.2 6.4 0 12.8 0 22.4 0 12.8 0 38.4 9.6 48-25.6 0-3.2 0-3.2 3.2-6.4 0-3.2 3.2-6.4 3.2-6.4 6.4-16 6.4-16 6.4-19.2 9.6-35.2 16-73.6 16-115.2 0-105.6-41.6-198.4-108.8-268.8C704 396.8 560 675.2 560 675.2zM224 419.2c0-28.8 22.4-51.2 51.2-51.2 28.8 0 51.2 22.4 51.2 51.2 0 28.8-22.4 51.2-51.2 51.2C246.4 470.4 224 448 224 419.2zM320 284.8c0-22.4 19.2-41.6 41.6-41.6 22.4 0 41.6 19.2 41.6 41.6 0 22.4-19.2 41.6-41.6 41.6C339.2 326.4 320 307.2 320 284.8zM457.6 208c0-12.8 12.8-25.6 25.6-25.6 12.8 0 25.6 12.8 25.6 25.6 0 12.8-12.8 25.6-25.6 25.6C470.4 233.6 457.6 220.8 457.6 208zM128 505.6C128 592 153.6 672 201.6 736c28.8-60.8 112-60.8 124.8-60.8-16-51.2 16-99.2 16-99.2l316.8-422.4c-48-19.2-99.2-32-150.4-32C297.6 118.4 128 291.2 128 505.6zM764.8 86.4c-22.4 19.2-390.4 518.4-390.4 518.4-22.4 28.8-12.8 76.8 22.4 99.2l9.6 6.4c35.2 22.4 80 12.8 99.2-25.6 0 0 6.4-12.8 9.6-19.2 54.4-105.6 275.2-524.8 288-553.6 6.4-19.2-3.2-32-19.2-32C777.6 76.8 771.2 80 764.8 86.4z"></path></svg><div class="outlook-dropdown"><!----></div></button></div><!--[--><div id="docsearch-container" style="display:none;"></div><div><button type="button" class="DocSearch DocSearch-Button" aria-label="搜索文档"><span class="DocSearch-Button-Container"><svg width="20" height="20" class="DocSearch-Search-Icon" viewBox="0 0 20 20"><path d="M14.386 14.386l4.0877 4.0877-4.0877-4.0877c-2.9418 2.9419-7.7115 2.9419-10.6533 0-2.9419-2.9418-2.9419-7.7115 0-10.6533 2.9418-2.9419 7.7115-2.9419 10.6533 0 2.9419 2.9418 2.9419 7.7115 0 10.6533z" stroke="currentColor" fill="none" fill-rule="evenodd" stroke-linecap="round" stroke-linejoin="round"></path></svg><span class="DocSearch-Button-Placeholder">搜索文档</span></span><span class="DocSearch-Button-Keys"><kbd class="DocSearch-Button-Key"><svg width="15" height="15" class="DocSearch-Control-Key-Icon"><path d="M4.505 4.496h2M5.505 5.496v5M8.216 4.496l.055 5.993M10 7.5c.333.333.5.667.5 1v2M12.326 4.5v5.996M8.384 4.496c1.674 0 2.116 0 2.116 1.5s-.442 1.5-2.116 1.5M3.205 9.303c-.09.448-.277 1.21-1.241 1.203C1 10.5.5 9.513.5 8V7c0-1.57.5-2.5 1.464-2.494.964.006 1.134.598 1.24 1.342M12.553 10.5h1.953" stroke-width="1.2" stroke="currentColor" fill="none" stroke-linecap="square"></path></svg></kbd><kbd class="DocSearch-Button-Key">K</kbd></span></button></div><!--]--><!--]--><!--[--><!----><!--]--><button type="button" class="vp-toggle-navbar-button" aria-label="Toggle Navbar" aria-expanded="false" aria-controls="nav-screen"><span><span class="vp-top"></span><span class="vp-middle"></span><span class="vp-bottom"></span></span></button></div></header><!----><!--]--><!----><div class="toggle-sidebar-wrapper"><span class="arrow start"></span></div><aside id="sidebar" class="vp-sidebar"><!--[--><!----><!--]--><ul class="vp-sidebar-links"><li><!--[--><a class="vp-link nav-link vp-sidebar-link vp-sidebar-page" href="/home.html"><!---->一、前言<!----></a><ul class="vp-sidebar-sub-headers"></ul><!--]--></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">二、Java基础</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">三、Java进阶</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">四、MySQL</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">五、Redis</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">六、计算机基础</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">七、求职面试</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">八、学习建议</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">九、知识库搭建</span><span class="vp-arrow end"></span></button><!----></section></li><li><section class="vp-sidebar-group"><button class="vp-sidebar-heading clickable" type="button"><!----><span class="vp-sidebar-title">十、联系作者</span><span class="vp-arrow end"></span></button><!----></section></li></ul><!--[--><!----><!--]--></aside><!--[--><main id="main-content" class="vp-page"><!--[--><!----><!----><nav class="vp-breadcrumb disable"></nav><div class="vp-page-title"><h1><!---->为什么重写equals方法的时候必须要重写hashCode方法？</h1><div class="page-info"><span class="page-author-info" aria-label="作者🖊" data-balloon-pos="down"><svg xmlns="http://www.w3.org/2000/svg" class="icon author-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="author icon"><path d="M649.6 633.6c86.4-48 147.2-144 147.2-249.6 0-160-128-288-288-288s-288 128-288 288c0 108.8 57.6 201.6 147.2 249.6-121.6 48-214.4 153.6-240 288-3.2 9.6 0 19.2 6.4 25.6 3.2 9.6 12.8 12.8 22.4 12.8h704c9.6 0 19.2-3.2 25.6-12.8 6.4-6.4 9.6-16 6.4-25.6-25.6-134.4-121.6-240-243.2-288z"></path></svg><span><a class="page-author-item" href="/about-the-author/" target="_blank" rel="noopener noreferrer">沉默王二</a></span><span property="author" content="沉默王二"></span></span><!----><span class="page-date-info" aria-label="写作日期📅" data-balloon-pos="down"><svg xmlns="http://www.w3.org/2000/svg" class="icon calendar-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="calendar icon"><path d="M716.4 110.137c0-18.753-14.72-33.473-33.472-33.473-18.753 0-33.473 14.72-33.473 33.473v33.473h66.993v-33.473zm-334.87 0c0-18.753-14.72-33.473-33.473-33.473s-33.52 14.72-33.52 33.473v33.473h66.993v-33.473zm468.81 33.52H716.4v100.465c0 18.753-14.72 33.473-33.472 33.473a33.145 33.145 0 01-33.473-33.473V143.657H381.53v100.465c0 18.753-14.72 33.473-33.473 33.473a33.145 33.145 0 01-33.473-33.473V143.657H180.6A134.314 134.314 0 0046.66 277.595v535.756A134.314 134.314 0 00180.6 947.289h669.74a134.36 134.36 0 00133.94-133.938V277.595a134.314 134.314 0 00-133.94-133.938zm33.473 267.877H147.126a33.145 33.145 0 01-33.473-33.473c0-18.752 14.72-33.473 33.473-33.473h736.687c18.752 0 33.472 14.72 33.472 33.473a33.145 33.145 0 01-33.472 33.473z"></path></svg><span><!----></span><meta property="datePublished" content="2021-10-22T07:22:10.000Z"></span><span class="page-category-info" aria-label="分类🌈" data-balloon-pos="down"><svg xmlns="http://www.w3.org/2000/svg" class="icon category-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="category icon"><path d="M148.41 106.992h282.176c22.263 0 40.31 18.048 40.31 40.31V429.48c0 22.263-18.047 40.31-40.31 40.31H148.41c-22.263 0-40.311-18.047-40.311-40.31V147.302c0-22.263 18.048-40.31 40.311-40.31zM147.556 553.478H429.73c22.263 0 40.311 18.048 40.311 40.31v282.176c0 22.263-18.048 40.312-40.31 40.312H147.555c-22.263 0-40.311-18.049-40.311-40.312V593.79c0-22.263 18.048-40.311 40.31-40.311zM593.927 106.992h282.176c22.263 0 40.31 18.048 40.31 40.31V429.48c0 22.263-18.047 40.31-40.31 40.31H593.927c-22.263 0-40.311-18.047-40.311-40.31V147.302c0-22.263 18.048-40.31 40.31-40.31zM730.22 920.502H623.926c-40.925 0-74.22-33.388-74.22-74.425V623.992c0-41.038 33.387-74.424 74.425-74.424h222.085c41.038 0 74.424 33.226 74.424 74.067v114.233c0 10.244-8.304 18.548-18.547 18.548s-18.548-8.304-18.548-18.548V623.635c0-20.388-16.746-36.974-37.33-36.974H624.13c-20.585 0-37.331 16.747-37.331 37.33v222.086c0 20.585 16.654 37.331 37.126 37.331H730.22c10.243 0 18.547 8.304 18.547 18.547 0 10.244-8.304 18.547-18.547 18.547z"></path></svg><!--[--><span class="page-category-item category0" role>Java核心</span><!--]--><meta property="articleSection" content="Java核心"></span><span class="page-tag-info" aria-label="标签🏷" data-balloon-pos="down"><svg xmlns="http://www.w3.org/2000/svg" class="icon tag-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="tag icon"><path d="M939.902 458.563L910.17 144.567c-1.507-16.272-14.465-29.13-30.737-30.737L565.438 84.098h-.402c-3.215 0-5.726 1.005-7.634 2.913l-470.39 470.39a10.004 10.004 0 000 14.164l365.423 365.424c1.909 1.908 4.42 2.913 7.132 2.913s5.223-1.005 7.132-2.913l470.39-470.39c2.01-2.11 3.014-5.023 2.813-8.036zm-240.067-72.121c-35.458 0-64.286-28.828-64.286-64.286s28.828-64.285 64.286-64.285 64.286 28.828 64.286 64.285-28.829 64.286-64.286 64.286z"></path></svg><!--[--><span class="page-tag-item tag3" role>Java重要知识点</span><!--]--><meta property="keywords" content="Java重要知识点"></span><span class="page-word-info" aria-label="字数🔠" data-balloon-pos="down"><svg xmlns="http://www.w3.org/2000/svg" class="icon word-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="word icon"><path d="M518.217 432.64V73.143A73.143 73.143 0 01603.43 1.097a512 512 0 01419.474 419.474 73.143 73.143 0 01-72.046 85.212H591.36a73.143 73.143 0 01-73.143-73.143z"></path><path d="M493.714 566.857h340.297a73.143 73.143 0 0173.143 85.577A457.143 457.143 0 11371.566 117.76a73.143 73.143 0 0185.577 73.143v339.383a36.571 36.571 0 0036.571 36.571z"></path></svg><span>约 2490 字</span><meta property="wordCount" content="2490"></span><span class="page-reading-time-info" aria-label="阅读时间⌛" data-balloon-pos="down"><svg xmlns="http://www.w3.org/2000/svg" class="icon timer-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="timer icon"><path d="M799.387 122.15c4.402-2.978 7.38-7.897 7.38-13.463v-1.165c0-8.933-7.38-16.312-16.312-16.312H256.33c-8.933 0-16.311 7.38-16.311 16.312v1.165c0 5.825 2.977 10.874 7.637 13.592 4.143 194.44 97.22 354.963 220.201 392.763-122.204 37.542-214.893 196.511-220.2 389.397-4.661 5.049-7.638 11.651-7.638 19.03v5.825h566.49v-5.825c0-7.379-2.849-13.981-7.509-18.9-5.049-193.016-97.867-351.985-220.2-389.527 123.24-37.67 216.446-198.453 220.588-392.892zM531.16 450.445v352.632c117.674 1.553 211.787 40.778 211.787 88.676H304.097c0-48.286 95.149-87.382 213.728-88.676V450.445c-93.077-3.107-167.901-81.297-167.901-177.093 0-8.803 6.99-15.793 15.793-15.793 8.803 0 15.794 6.99 15.794 15.793 0 80.261 63.69 145.635 142.01 145.635s142.011-65.374 142.011-145.635c0-8.803 6.99-15.793 15.794-15.793s15.793 6.99 15.793 15.793c0 95.019-73.789 172.82-165.96 177.093z"></path></svg><span>大约 8 分钟</span><meta property="timeRequired" content="PT8M"></span></div><hr></div><!----><!----><div class="theme-hope-content"><h1 id="_13-5-为什么重写equals的时候必须重写hashcode" tabindex="-1"><a class="header-anchor" href="#_13-5-为什么重写equals的时候必须重写hashcode" aria-hidden="true">#</a> 13.5 为什么重写equals的时候必须重写hashCode</h1><p>“二哥，我在读《Effective Java》 的时候，第 11 条规约说重写 equals 的时候必须要重写 hashCode 方法，这是为什么呀？”三妹单刀直入地问。</p><p>“三妹啊，这个问题问得非常好，因为它也是面试中经常考的一个知识点。今天哥就带你来梳理一下。”我说。</p><p>Java 是一门面向对象的编程语言，所有的类都会默认继承自 <a href="https://javabetter.cn/oo/object-class.html" target="_blank" rel="noopener noreferrer">Object 类<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>，而 Object 的中文意思就是“对象”。</p><p>Object 类中有这么两个方法：</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">public</span> <span class="token keyword">native</span> <span class="token keyword">int</span> <span class="token function">hashCode</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">public</span> <span class="token keyword">boolean</span> <span class="token function">equals</span><span class="token punctuation">(</span><span class="token class-name">Object</span> obj<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">return</span> <span class="token punctuation">(</span><span class="token keyword">this</span> <span class="token operator">==</span> obj<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p><strong>1）hashCode 方法</strong></p><p>这是一个本地方法，用来返回对象的哈希值（一个整数）。在 Java 程序执行期间，对同一个对象多次调用该方法必须返回相同的哈希值。</p><p><strong>2）equals 方法</strong></p><p>对于任何非空引用 x 和 y，当且仅当 x 和 y 引用的是同一个对象时，equals 方法才返回 true。</p><p>“二哥，看起来两个方法之间没有任何关联啊？”三妹质疑道。</p><p>“单从这两段解释上来看，的确是这样的。”我解释道，“但两个方法的 doc 文档中还有这样两条信息。”</p><p>第一，如果两个对象调用 equals 方法返回的结果为 true，那么两个对象调用 hashCode 方法返回的结果也必然相同——来自 hashCode 方法的 doc 文档。</p><p>第二，每当重写 <a href="https://javabetter.cn/string/equals.html" target="_blank" rel="noopener noreferrer">equals 方法<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>时，<a href="https://javabetter.cn/basic-extra-meal/hashcode.html" target="_blank" rel="noopener noreferrer">hashCode 方法<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>也需要重写，以便维护上一条规约。</p><p>“哦，这样讲的话，两个方法确实关联上了，但究竟是为什么呢？”三妹抛出了终极一问。</p><p>“hashCode 方法的作用是用来获取哈希值，而该哈希值的作用是用来确定<a href="https://javabetter.cn/collection/hashmap.html" target="_blank" rel="noopener noreferrer">对象在哈希表中的索引位置（HashMap 的时候会讲）<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>。”我说。</p><p>哈希表的典型代表就是 <a href="https://javabetter.cn/collection/hashmap.html" target="_blank" rel="noopener noreferrer">HashMap<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>，它存储的是键值对，能根据键快速地检索出对应的值。</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">public</span> <span class="token class-name">V</span> <span class="token function">get</span><span class="token punctuation">(</span><span class="token class-name">Object</span> key<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token class-name">HashMap<span class="token punctuation">.</span>Node</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span> e<span class="token punctuation">;</span>
<span class="token keyword">return</span> <span class="token punctuation">(</span>e <span class="token operator">=</span> <span class="token function">getNode</span><span class="token punctuation">(</span><span class="token function">hash</span><span class="token punctuation">(</span>key<span class="token punctuation">)</span><span class="token punctuation">,</span> key<span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token operator">==</span> <span class="token keyword">null</span> <span class="token operator">?</span> <span class="token keyword">null</span> <span class="token operator">:</span> e<span class="token punctuation">.</span>value<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>这是 HashMap 的 get 方法，通过键来获取值的方法。它会调用 getNode 方法：</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token class-name">HashMap<span class="token punctuation">.</span>Node</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span> <span class="token function">getNode</span><span class="token punctuation">(</span><span class="token keyword">int</span> hash<span class="token punctuation">,</span> <span class="token class-name">Object</span> key<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token class-name">HashMap<span class="token punctuation">.</span>Node</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span><span class="token punctuation">[</span><span class="token punctuation">]</span> tab<span class="token punctuation">;</span> <span class="token class-name">HashMap<span class="token punctuation">.</span>Node</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span> first<span class="token punctuation">,</span> e<span class="token punctuation">;</span> <span class="token keyword">int</span> n<span class="token punctuation">;</span> <span class="token class-name">K</span> k<span class="token punctuation">;</span>
<span class="token comment">// 判断 HashMap 的 table 是否为 null 以及 table 长度是否大于 0</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token punctuation">(</span>tab <span class="token operator">=</span> table<span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token keyword">null</span> <span class="token operator">&&</span> <span class="token punctuation">(</span>n <span class="token operator">=</span> tab<span class="token punctuation">.</span>length<span class="token punctuation">)</span> <span class="token operator">></span> <span class="token number">0</span> <span class="token operator">&&</span>
<span class="token comment">// 根据 hash 值计算出在 table 中的索引位置，并获取第一个节点</span>
<span class="token punctuation">(</span>first <span class="token operator">=</span> tab<span class="token punctuation">[</span><span class="token punctuation">(</span>n <span class="token operator">-</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token operator">&</span> hash<span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token keyword">null</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token comment">// 判断第一个节点的 hash 值是否与给定 hash 相等，如果相等，则检查 key 是否相等</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>first<span class="token punctuation">.</span>hash <span class="token operator">==</span> hash <span class="token operator">&&</span>
<span class="token punctuation">(</span><span class="token punctuation">(</span>k <span class="token operator">=</span> first<span class="token punctuation">.</span>key<span class="token punctuation">)</span> <span class="token operator">==</span> key <span class="token operator">||</span> <span class="token punctuation">(</span>key <span class="token operator">!=</span> <span class="token keyword">null</span> <span class="token operator">&&</span> key<span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>k<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> first<span class="token punctuation">;</span>
<span class="token comment">// 如果不相等，获取当前节点的下一个节点</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token punctuation">(</span>e <span class="token operator">=</span> first<span class="token punctuation">.</span>next<span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token keyword">null</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token comment">// 如果当前节点为 TreeNode 类型（红黑树），则调用 TreeNode 的 getTreeNode 方法查找</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>first <span class="token keyword">instanceof</span> <span class="token class-name">HashMap<span class="token punctuation">.</span>TreeNode</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> <span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token class-name">HashMap<span class="token punctuation">.</span>TreeNode</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span><span class="token punctuation">)</span>first<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getTreeNode</span><span class="token punctuation">(</span>hash<span class="token punctuation">,</span> key<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token comment">// 如果不是红黑树节点，遍历链表查找</span>
<span class="token keyword">do</span> <span class="token punctuation">{</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>e<span class="token punctuation">.</span>hash <span class="token operator">==</span> hash <span class="token operator">&&</span>
<span class="token punctuation">(</span><span class="token punctuation">(</span>k <span class="token operator">=</span> e<span class="token punctuation">.</span>key<span class="token punctuation">)</span> <span class="token operator">==</span> key <span class="token operator">||</span> <span class="token punctuation">(</span>key <span class="token operator">!=</span> <span class="token keyword">null</span> <span class="token operator">&&</span> key<span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>k<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> e<span class="token punctuation">;</span>
<span class="token punctuation">}</span> <span class="token keyword">while</span> <span class="token punctuation">(</span><span class="token punctuation">(</span>e <span class="token operator">=</span> e<span class="token punctuation">.</span>next<span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token keyword">null</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token punctuation">}</span>
<span class="token comment">// 如果没有找到对应的节点，则返回 null</span>
<span class="token keyword">return</span> <span class="token keyword">null</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>通常情况（没有发生哈希冲突）下，<code>first = tab[(n - 1) & hash]</code> 就是键对应的值。<strong>按照时间复杂度来说的话，可表示为 O(1)</strong>。</p><p>如果发生哈希冲突，也就是 <code>if ((e = first.next) != null) {}</code> 子句中，可以看到如果节点不是红黑树的时候，会通过 do-while 循环语句判断键是否 equals 返回对应值的。<strong>按照时间复杂度来说的话，可表示为 O(n)</strong>。</p><p>HashMap 是通过拉链法来解决哈希冲突的，也就是如果发生哈希冲突，同一个键的坑位会放好多个值，超过 8 个值后改为红黑树，为了提高查询的效率。</p><p>显然，从时间复杂度上来看的话 O(n) 比 O(1) 的性能要差，这也正是哈希表的价值所在。</p><p>“O(n) 和 O(1) 是什么呀？”三妹有些不解。</p><p>“这是<a href="https://javabetter.cn/collection/time-complexity.html" target="_blank" rel="noopener noreferrer">时间复杂度<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>的一种表示方法，随后二哥专门给你讲一下。简单说一下 n 和 1 的意思，很显然，n 和 1 都代表的是代码执行的次数，假如数据规模为 n，n 就代表需要执行 n 次，1 就代表只需要执行一次。”我解释道。</p><p>“三妹，你想一下，如果没有哈希表，但又需要这样一个数据结构，它里面存放的数据是不允许重复的，该怎么办呢？”我问。</p><p>“要不使用 equals 方法进行逐个比较？”三妹有些不太确定。</p><p>“这种方法当然是可行的，就像 <code>if ((e = first.next) != null) {}</code> 子句中那样，但如果数据量特别特别大，性能就会很差，最好的解决方案还是 HashMap。”</p><p>HashMap 本质上是通过<a href="https://javabetter.cn/array/array.html" target="_blank" rel="noopener noreferrer">数组<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>实现的，当我们要从 HashMap 中获取某个值时，实际上是要获取数组中某个位置的元素，而位置是通过键来确定的。</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">public</span> <span class="token class-name">V</span> <span class="token function">put</span><span class="token punctuation">(</span><span class="token class-name">K</span> key<span class="token punctuation">,</span> <span class="token class-name">V</span> value<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">return</span> <span class="token function">putVal</span><span class="token punctuation">(</span><span class="token function">hash</span><span class="token punctuation">(</span>key<span class="token punctuation">)</span><span class="token punctuation">,</span> key<span class="token punctuation">,</span> value<span class="token punctuation">,</span> <span class="token boolean">false</span><span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>这是 HashMap 的 put 方法，会将键值对放入到数组当中。它会调用 putVal 方法：</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">final</span> <span class="token class-name">HashMap<span class="token punctuation">.</span>Node</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span> <span class="token function">getNode</span><span class="token punctuation">(</span><span class="token keyword">int</span> hash<span class="token punctuation">,</span> <span class="token class-name">Object</span> key<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token class-name">HashMap<span class="token punctuation">.</span>Node</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span><span class="token punctuation">[</span><span class="token punctuation">]</span> tab<span class="token punctuation">;</span> <span class="token class-name">HashMap<span class="token punctuation">.</span>Node</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span> first<span class="token punctuation">,</span> e<span class="token punctuation">;</span> <span class="token keyword">int</span> n<span class="token punctuation">;</span> <span class="token class-name">K</span> k<span class="token punctuation">;</span>
<span class="token comment">// 判断 HashMap 的 table 是否为 null 以及 table 长度是否大于 0</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token punctuation">(</span>tab <span class="token operator">=</span> table<span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token keyword">null</span> <span class="token operator">&&</span> <span class="token punctuation">(</span>n <span class="token operator">=</span> tab<span class="token punctuation">.</span>length<span class="token punctuation">)</span> <span class="token operator">></span> <span class="token number">0</span> <span class="token operator">&&</span>
<span class="token comment">// 根据 hash 值计算出在 table 中的索引位置，并获取第一个节点</span>
<span class="token punctuation">(</span>first <span class="token operator">=</span> tab<span class="token punctuation">[</span><span class="token punctuation">(</span>n <span class="token operator">-</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token operator">&</span> hash<span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token keyword">null</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token comment">// 判断第一个节点的 hash 值是否与给定 hash 相等，如果相等，则检查 key 是否相等</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>first<span class="token punctuation">.</span>hash <span class="token operator">==</span> hash <span class="token operator">&&</span>
<span class="token punctuation">(</span><span class="token punctuation">(</span>k <span class="token operator">=</span> first<span class="token punctuation">.</span>key<span class="token punctuation">)</span> <span class="token operator">==</span> key <span class="token operator">||</span> <span class="token punctuation">(</span>key <span class="token operator">!=</span> <span class="token keyword">null</span> <span class="token operator">&&</span> key<span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>k<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> first<span class="token punctuation">;</span>
<span class="token comment">// 如果不相等，获取当前节点的下一个节点</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token punctuation">(</span>e <span class="token operator">=</span> first<span class="token punctuation">.</span>next<span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token keyword">null</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token comment">// 如果当前节点为 TreeNode 类型（红黑树），则调用 TreeNode 的 getTreeNode 方法查找</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>first <span class="token keyword">instanceof</span> <span class="token class-name">HashMap<span class="token punctuation">.</span>TreeNode</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> <span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token class-name">HashMap<span class="token punctuation">.</span>TreeNode</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">K</span><span class="token punctuation">,</span><span class="token class-name">V</span><span class="token punctuation">></span></span><span class="token punctuation">)</span>first<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getTreeNode</span><span class="token punctuation">(</span>hash<span class="token punctuation">,</span> key<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token comment">// 如果不是红黑树节点，遍历链表查找</span>
<span class="token keyword">do</span> <span class="token punctuation">{</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>e<span class="token punctuation">.</span>hash <span class="token operator">==</span> hash <span class="token operator">&&</span>
<span class="token punctuation">(</span><span class="token punctuation">(</span>k <span class="token operator">=</span> e<span class="token punctuation">.</span>key<span class="token punctuation">)</span> <span class="token operator">==</span> key <span class="token operator">||</span> <span class="token punctuation">(</span>key <span class="token operator">!=</span> <span class="token keyword">null</span> <span class="token operator">&&</span> key<span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>k<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> e<span class="token punctuation">;</span>
<span class="token punctuation">}</span> <span class="token keyword">while</span> <span class="token punctuation">(</span><span class="token punctuation">(</span>e <span class="token operator">=</span> e<span class="token punctuation">.</span>next<span class="token punctuation">)</span> <span class="token operator">!=</span> <span class="token keyword">null</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token punctuation">}</span>
<span class="token comment">// 如果没有找到对应的节点，则返回 null</span>
<span class="token keyword">return</span> <span class="token keyword">null</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>通常情况下，<code>p = tab[i = (n - 1) & hash])</code> 就是键对应的值。而数组的索引 <code>(n - 1) & hash</code> 正是基于 hashCode 方法计算得到的。</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">static</span> <span class="token keyword">final</span> <span class="token keyword">int</span> <span class="token function">hash</span><span class="token punctuation">(</span><span class="token class-name">Object</span> key<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">int</span> h<span class="token punctuation">;</span>
<span class="token keyword">return</span> <span class="token punctuation">(</span>key <span class="token operator">==</span> <span class="token keyword">null</span><span class="token punctuation">)</span> <span class="token operator">?</span> <span class="token number">0</span> <span class="token operator">:</span> <span class="token punctuation">(</span>h <span class="token operator">=</span> key<span class="token punctuation">.</span><span class="token function">hashCode</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token operator">^</span> <span class="token punctuation">(</span>h <span class="token operator">>>></span> <span class="token number">16</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>“那二哥，你好像还是没有说为什么重写 equals 方法的时候要重写 hashCode 方法呀？”三妹忍不住了。</p><p>“来看下面这段代码。”我说。</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Test</span> <span class="token punctuation">{</span>
<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">main</span><span class="token punctuation">(</span><span class="token class-name">String</span><span class="token punctuation">[</span><span class="token punctuation">]</span> args<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token class-name">Student</span> s1 <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Student</span><span class="token punctuation">(</span><span class="token number">18</span><span class="token punctuation">,</span> <span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">Map</span><span class="token generics"><span class="token punctuation"><</span><span class="token class-name">Student</span><span class="token punctuation">,</span> <span class="token class-name">Integer</span><span class="token punctuation">></span></span> scores <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token generics"><span class="token punctuation"><</span><span class="token punctuation">></span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
scores<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>s1<span class="token punctuation">,</span> <span class="token number">98</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">Student</span> s2 <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Student</span><span class="token punctuation">(</span><span class="token number">18</span><span class="token punctuation">,</span> <span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>scores<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span>s2<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token punctuation">}</span>
<span class="token keyword">class</span> <span class="token class-name">Student</span> <span class="token punctuation">{</span>
<span class="token keyword">private</span> <span class="token keyword">int</span> age<span class="token punctuation">;</span>
<span class="token keyword">private</span> <span class="token class-name">String</span> name<span class="token punctuation">;</span>
<span class="token keyword">public</span> <span class="token class-name">Student</span><span class="token punctuation">(</span><span class="token keyword">int</span> age<span class="token punctuation">,</span> <span class="token class-name">String</span> name<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>age <span class="token operator">=</span> age<span class="token punctuation">;</span>
<span class="token keyword">this</span><span class="token punctuation">.</span>name <span class="token operator">=</span> name<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> <span class="token keyword">boolean</span> <span class="token function">equals</span><span class="token punctuation">(</span><span class="token class-name">Object</span> o<span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token class-name">Student</span> student <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token class-name">Student</span><span class="token punctuation">)</span> o<span class="token punctuation">;</span>
<span class="token keyword">return</span> age <span class="token operator">==</span> student<span class="token punctuation">.</span>age <span class="token operator">&&</span>
<span class="token class-name">Objects</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> student<span class="token punctuation">.</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>我们重写了 Student 类的 equals 方法，如果两个学生的年纪和姓名相同，我们就认为是同一个学生，虽然很离谱，但我们就是这么草率。</p><p>在 main 方法中，18 岁的张三考试得了 98 分，很不错的成绩，我们把张三和他的成绩放到 HashMap 中，然后准备取出：</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>null
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>“二哥，怎么输出了 null，而不是预期当中的 98 呢？”三妹感到很不可思议。</p><p>“原因就在于重写 equals 方法的时候没有重写 hashCode 方法。”我回答道，“equals 方法虽然认定名字和年纪相同就是同一个学生，但它们本质上是两个对象，hashCode 并不相同。”</p><figure><img src="https://cdn.tobebetterjavaer.com/tobebetterjavaer/images/core-points/equals-hashcode-01.png" alt="" tabindex="0" loading="lazy"><figcaption></figcaption></figure><p>“那怎么重写 hashCode 方法呢？”三妹问。</p><p>“可以直接调用 Objects 类的 hash 方法。”我回答。</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code> <span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">hashCode</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">return</span> <span class="token class-name">Objects</span><span class="token punctuation">.</span><span class="token function">hash</span><span class="token punctuation">(</span>age<span class="token punctuation">,</span> name<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>Objects 类的 hash 方法可以针对不同数量的参数生成新的哈希值，hash 方法调用的是 Arrays 类的 hashCode 方法，该方法源码如下：</p><div class="language-java line-numbers-mode" data-ext="java"><pre class="language-java"><code><span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">int</span> <span class="token function">hashCode</span><span class="token punctuation">(</span><span class="token class-name">Object</span> a<span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>a <span class="token operator">==</span> <span class="token keyword">null</span><span class="token punctuation">)</span>
<span class="token keyword">return</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token keyword">int</span> result <span class="token operator">=</span> <span class="token number">1</span><span class="token punctuation">;</span>
<span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token class-name">Object</span> element <span class="token operator">:</span> a<span class="token punctuation">)</span>
result <span class="token operator">=</span> <span class="token number">31</span> <span class="token operator">*</span> result <span class="token operator">+</span> <span class="token punctuation">(</span>element <span class="token operator">==</span> <span class="token keyword">null</span> <span class="token operator">?</span> <span class="token number">0</span> <span class="token operator">:</span> element<span class="token punctuation">.</span><span class="token function">hashCode</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">return</span> result<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>第一次循环：</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>result = 31*1 + Integer(18).hashCode();
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>第二次循环：</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>result = (31*1 + Integer(18).hashCode()) * 31 + String("张三").hashCode();
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>针对姓名年纪不同的对象，这样计算后的哈希值很难很难很难重复的；针对姓名年纪相同的对象，哈希值保持一致。</p><p>再次执行 main 方法，结果如下所示：</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>98
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>因为此时 s1 和 s2 对象的哈希值都为 776408。</p><figure><img src="https://cdn.tobebetterjavaer.com/tobebetterjavaer/images/core-points/equals-hashcode-02.png" alt="" tabindex="0" loading="lazy"><figcaption></figcaption></figure><p>“每当重写 equals 方法时，hashCode 方法也需要重写，原因就是为了保证：如果两个对象调用 equals 方法返回的结果为 true，那么两个对象调用 hashCode 方法返回的结果也必然相同。”我点题了。</p><p>“OK，get 了。”三妹开心地点了点头，看得出来，今天学到了不少。</p><hr><p>GitHub 上标星 10000+ 的开源知识库《<a href="https://github.com/itwanger/toBeBetterJavaer" target="_blank" rel="noopener noreferrer">二哥的 Java 进阶之路<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a>》第一版 PDF 终于来了！包括Java基础语法、数组&字符串、OOP、集合框架、Java IO、异常处理、Java 新特性、网络编程、NIO、并发编程、JVM等等，共计 32 万余字，500+张手绘图，可以说是通俗易懂、风趣幽默……详情戳：<a href="https://javabetter.cn/overview/" target="_blank" rel="noopener noreferrer">太赞了，GitHub 上标星 10000+ 的 Java 教程<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span></a></p><p>微信搜 <strong>沉默王二</strong> 或扫描下方二维码关注二哥的原创公众号沉默王二，回复 <strong>222</strong> 即可免费领取。</p><figure><img src="https://cdn.tobebetterjavaer.com/tobebetterjavaer/images/gongzhonghao.png" alt="" tabindex="0" loading="lazy"><figcaption></figcaption></figure></div><!----><footer class="page-meta"><div class="meta-item edit-link"><a href="https://github.com/itwanger/toBeBetterJavaer/edit/master/docs/basic-extra-meal/equals-hashcode.md" rel="noopener noreferrer" target="_blank" aria-label="编辑此页" class="nav-link label"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon edit-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="edit icon"><path d="M430.818 653.65a60.46 60.46 0 0 1-50.96-93.281l71.69-114.012 7.773-10.365L816.038 80.138A60.46 60.46 0 0 1 859.225 62a60.46 60.46 0 0 1 43.186 18.138l43.186 43.186a60.46 60.46 0 0 1 0 86.373L588.879 565.55l-8.637 8.637-117.466 68.234a60.46 60.46 0 0 1-31.958 11.229z"></path><path d="M728.802 962H252.891A190.883 190.883 0 0 1 62.008 771.98V296.934a190.883 190.883 0 0 1 190.883-192.61h267.754a60.46 60.46 0 0 1 0 120.92H252.891a69.962 69.962 0 0 0-69.098 69.099V771.98a69.962 69.962 0 0 0 69.098 69.098h475.911A69.962 69.962 0 0 0 797.9 771.98V503.363a60.46 60.46 0 1 1 120.922 0V771.98A190.883 190.883 0 0 1 728.802 962z"></path></svg><!--]-->编辑此页<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="meta-item git-info"><div class="update-time"><span class="label">上次编辑于: </span><!----></div><div class="contributors"><span class="label">贡献者: </span><!--[--><!--[--><span class="contributor" title="email: www.qing_gee@163.com">itwanger</span>,<!--]--><!--[--><span class="contributor" title="email: www.qing_gee@163.com">沉默王二</span><!--]--><!--]--></div></div></footer><!----><div id="comment" class="giscus-wrapper input-top" style="display:block;"><div class="loading-icon-wrapper" style="display:flex;align-items:center;justify-content:center;height:96px"><svg xmlns="http://www.w3.org/2000/svg" width="48" height="48" preserveAspectRatio="xMidYMid" viewBox="25 25 50 50"><animateTransform attributeName="transform" type="rotate" dur="2s" keyTimes="0;1" repeatCount="indefinite" values="0;360"></animateTransform><circle cx="50" cy="50" r="20" fill="none" stroke="currentColor" stroke-width="4" stroke-linecap="round"><animate attributeName="stroke-dasharray" dur="1.5s" keyTimes="0;0.5;1" repeatCount="indefinite" values="1,200;90,200;1,200"></animate><animate attributeName="stroke-dashoffset" dur="1.5s" keyTimes="0;0.5;1" repeatCount="indefinite" values="0;-35px;-125px"></animate></circle></svg></div></div><!----><!--]--></main><!--]--><footer class="vp-footer-wrapper"><div class="vp-footer"><a href="https://beian.miit.gov.cn/" target="_blank">豫ICP备2021038026号-4</a><img src="https://cdn.tobebetterjavaer.com/tobebetterjavaer/images/beian.png" height="15px" width="15px" /><a target="_blank" href="http://www.beian.gov.cn/portal/registerSystemInfo?recordcode=41030502000411"><span>豫公网安备 41030502000411号</span></a></div><div class="vp-copyright">Copyright © 2024 沉默王二</div></footer></div><!--]--><!----><!----><!--]--></div>
<script type="module" src="/assets/app-dea8ffe7.js" defer></script>
</body>
</html>