diff --git a/CHANGELOG.md b/CHANGELOG.md
index 85e69e3a..70086595 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,10 @@
 # Changelog
+## 7.15.0（2023-12-25)
+* 区域缓存支持磁盘缓存
+* 提供快速生成公有云的区域实例的方法
+* batch 操作接口增强
+* 支持归档直读
+
 ## 7.14.0（2023-07-18)
 * Region 移除亚太首尔区域
 * BucketManager 的部分 Bucket 级别接口支持主备重试
diff --git a/README.md b/README.md
index d30d2398..fa22979b 100644
--- a/README.md
+++ b/README.md
@@ -13,12 +13,12 @@
 <dependency>
   <groupId>com.qiniu</groupId>
   <artifactId>qiniu-java-sdk</artifactId>
-  <version>[7.14.0, 7.14.99]</version>
+  <version>[7.15.0, 7.15.99]</version>
 </dependency>
 ```
 或者 Gradle:
 ```groovy
-implementation 'com.qiniu:qiniu-java-sdk:7.14.+'
+implementation 'com.qiniu:qiniu-java-sdk:7.15.+'
 ```
 
 ## 运行环境
diff --git a/src/main/java/com/qiniu/common/Constants.java b/src/main/java/com/qiniu/common/Constants.java
index e97887af..3441e977 100644
--- a/src/main/java/com/qiniu/common/Constants.java
+++ b/src/main/java/com/qiniu/common/Constants.java
@@ -10,7 +10,7 @@ public final class Constants {
     /**
      * 版本号
      */
-    public static final String VERSION = "7.14.0";
+    public static final String VERSION = "7.15.0";
     /**
      * 块大小，不能改变
      */
diff --git a/src/main/java/com/qiniu/util/DefaultHeader.java b/src/main/java/com/qiniu/util/DefaultHeader.java
index 95cc9df8..1e520363 100644
--- a/src/main/java/com/qiniu/util/DefaultHeader.java
+++ b/src/main/java/com/qiniu/util/DefaultHeader.java
@@ -5,6 +5,7 @@
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.Date;
+import java.util.Locale;
 import java.util.TimeZone;
 
 public final class DefaultHeader {
@@ -35,7 +36,7 @@ private static boolean isDisableQiniuTimestampSignature() {
     }
 
     private static String xQiniuDate() {
-        DateFormat format = new SimpleDateFormat("yyyyMMdd'T'HHmmss'Z'");
+        DateFormat format = new SimpleDateFormat("yyyyMMdd'T'HHmmss'Z'", Locale.US);
         format.setTimeZone(TimeZone.getTimeZone("UTC"));
         return format.format(new Date());
     }
diff --git a/src/test/java/test/com/qiniu/storage/BucketTest.java b/src/test/java/test/com/qiniu/storage/BucketTest.java
index 6e0e1356..01ac6115 100644
--- a/src/test/java/test/com/qiniu/storage/BucketTest.java
+++ b/src/test/java/test/com/qiniu/storage/BucketTest.java
@@ -6,9 +6,7 @@
 import com.qiniu.http.Response;
 import com.qiniu.storage.BucketManager;
 import com.qiniu.storage.Configuration;
-import com.qiniu.storage.Region;
 import com.qiniu.storage.model.*;
-import com.qiniu.util.Auth;
 import com.qiniu.util.Json;
 import com.qiniu.util.StringUtils;
 import okhttp3.Call;