优化 GreenDao 初始化位置，单独封装成类

HanteIsHante · May 3, 2017 · 09a1067 · 09a1067
1 parent ea992a2
commit 09a1067
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Showing 4 changed files with 49 additions and 33 deletions.
diff --git a/app/src/main/java/com/example/hante/thirdopen/application/GreenDaoManager.java b/app/src/main/java/com/example/hante/thirdopen/application/GreenDaoManager.java
@@ -0,0 +1,44 @@
+package com.example.hante.thirdopen.application;
+
+import android.content.Context;
+import android.database.sqlite.SQLiteDatabase;
+
+import com.example.hante.greendao.DaoMaster;
+import com.example.hante.greendao.DaoSession;
+
+/**
+ *  GreenDao  管理类
+ */
+
+public class GreenDaoManager {
+
+    private static GreenDaoManager INSTANCE;
+    private static DaoSession mDaoSession;
+
+    public static GreenDaoManager getINSTANCE(){
+        if(INSTANCE == null) {
+            synchronized(GreenDaoManager.class){
+                if(INSTANCE == null) {
+                    INSTANCE = new GreenDaoManager();
+                }
+            }
+        }
+        return INSTANCE;
+    }
+
+    static void init(Context context){
+        String DB_NAME = "thirdOpen-db";
+        // 通过DaoMaster 的内部类 DevOpenHelper，你可以得到一个便利的SQLiteOpenHelper 对象。
+        // 可能你已经注意到了，你并不需要去编写「CREATE TABLE」这样的 SQL 语句，因为greenDAO 已经帮你做了。
+        // 注意：默认的DaoMaster.DevOpenHelper 会在数据库升级时，删除所有的表，意味着这将导致数据的丢失。
+        // 所以，在正式的项目中，你还应该做一层封装，来实现数据库的安全升级。
+        DaoMaster.DevOpenHelper mDevOpenHelper = new DaoMaster.DevOpenHelper(context, DB_NAME,
+                null);
+        SQLiteDatabase mDatabase  = mDevOpenHelper.getWritableDatabase();
+        DaoMaster mDaoMaster = new DaoMaster(mDatabase);
+        mDaoSession = mDaoMaster.newSession();
+    }
+    public DaoSession getDaoSession() {
+        return mDaoSession;
+    }
+}
diff --git a/app/src/main/java/com/example/hante/thirdopen/application/MyApplication.java b/app/src/main/java/com/example/hante/thirdopen/application/MyApplication.java
@@ -3,10 +3,7 @@
 import android.app.Activity;
 import android.app.Application;
 import android.content.Context;
-import android.database.sqlite.SQLiteDatabase;
 
-import com.example.hante.greendao.DaoMaster;
-import com.example.hante.greendao.DaoSession;
 import com.example.hante.thirdopen.util.LogUtils;
 import com.squareup.leakcanary.LeakCanary;
 
@@ -27,10 +24,6 @@ public class MyApplication extends Application {
     private static MyApplication instance;
     private static Context mContext;
 
-    private SQLiteDatabase mDatabase;
-    private DaoSession mDaoSession;
-
-
     @Override
     public void onCreate () {
         super.onCreate();
@@ -41,29 +34,8 @@ public void onCreate () {
         instance = this;
         mContext = getApplicationContext();
         new LogUtils.Builder();
-        setDataBase();
-    }
-
-    private void setDataBase () {
-        // 通过DaoMaster 的内部类 DevOpenHelper，你可以得到一个便利的SQLiteOpenHelper 对象。
-        // 可能你已经注意到了，你并不需要去编写「CREATE TABLE」这样的 SQL 语句，因为greenDAO 已经帮你做了。
-        // 注意：默认的DaoMaster.DevOpenHelper 会在数据库升级时，删除所有的表，意味着这将导致数据的丢失。
-        // 所以，在正式的项目中，你还应该做一层封装，来实现数据库的安全升级。
-        DaoMaster.DevOpenHelper mDevOpenHelper = new DaoMaster.DevOpenHelper(this, "thirdOpen-db", null);
-        mDatabase  = mDevOpenHelper.getWritableDatabase();
-        DaoMaster mDaoMaster = new DaoMaster(mDatabase);
-        mDaoSession = mDaoMaster.newSession();
-    }
-
-    public DaoSession getDaoSession() {
-        return mDaoSession;
+        GreenDaoManager.init(this);  //  初始化 greenao 管理类
     }
-
-
-    public SQLiteDatabase getDb() {
-        return mDatabase;
-    }
-
     /**
      * 获取Application 实例
      *

diff --git a/app/src/main/java/com/example/hante/thirdopen/useractivity/LoginActivity.java b/app/src/main/java/com/example/hante/thirdopen/useractivity/LoginActivity.java
@@ -12,7 +12,7 @@
 import com.example.hante.greendao.UserDao;
 import com.example.hante.thirdopen.R;
 import com.example.hante.thirdopen.ThirdOpenHomeActivity;
-import com.example.hante.thirdopen.application.MyApplication;
+import com.example.hante.thirdopen.application.GreenDaoManager;
 import com.example.hante.thirdopen.db.bean.User;
 import com.example.hante.thirdopen.util.Utils;
 
@@ -39,7 +39,7 @@ protected void onCreate (Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_login);
         ButterKnife.bind(this);
-        mUserDao = MyApplication.getInstance().getDaoSession().getUserDao();
+        mUserDao = GreenDaoManager.getINSTANCE().getDaoSession().getUserDao();
     }
 
     @OnClick({R.id.button_login, R.id.to_register})

diff --git a/app/src/main/java/com/example/hante/thirdopen/useractivity/RegisterActivity.java b/app/src/main/java/com/example/hante/thirdopen/useractivity/RegisterActivity.java
@@ -10,7 +10,7 @@
 
 import com.example.hante.greendao.UserDao;
 import com.example.hante.thirdopen.R;
-import com.example.hante.thirdopen.application.MyApplication;
+import com.example.hante.thirdopen.application.GreenDaoManager;
 import com.example.hante.thirdopen.db.bean.User;
 import com.example.hante.thirdopen.util.Utils;
 
@@ -39,7 +39,7 @@ protected void onCreate (Bundle savedInstanceState) {
         setContentView(R.layout.activity_register);
         ButterKnife.bind(this);
         initUI();
-        mUserDao = MyApplication.getInstance().getDaoSession().getUserDao();
+        mUserDao = GreenDaoManager.getINSTANCE().getDaoSession().getUserDao();
     }
 
     private void initUI () {