应用程序没有关闭在此处打开的游标或数据库对象：答案

【问题标题】：Application did not close the cursor or database object that was opened here :应用程序没有关闭在此处打开的游标或数据库对象：
【发布时间】：2011-06-26 20:17:01
【问题描述】：

我的代码是：

public class EventDataSQLHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "my.db";
}

public class Test extends Activity {
    EventDataSQLHelper eventsData;

    @Override
    protected void onDestroy() {
        System.out.println("onDestroy");
  
        close();
        if (db!=null){
       
        db.close();
        
    }
    super.onDestroy();
}

public void close() {
    eventsData.close();
}

我已经在这里关闭了数据库。在我所有的活动中，除了这个它正在工作（没有显示异常）。在这里，当我从这个测试活动中按下返回按钮时，会引发以下异常

02-14 15:59:34.642: ERROR/Database(535): close() was never explicitly called on database '/data/data/com.tesy.connect/databases/test.db' 
02-14 15:59:34.642: ERROR/Database(535): android.database.sqlite.DatabaseObjectNotClosedException: Application did not close the cursor or database object that was opened here
02-14 15:59:34.642: ERROR/Database(535):     at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1810)
02-14 15:59:34.642: ERROR/Database(535):     at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:817)
02-14 15:59:34.642: ERROR/Database(535):     at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:851)
02-14 15:59:34.642: ERROR/Database(535):     at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:844)
02-14 15:59:34.642: ERROR/Database(535):     at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:540)
02-14 15:59:34.642: ERROR/Database(535):     at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:203)
02-14 15:59:34.642: ERROR/Database(535):     at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:98)
02-14 15:59:34.642: ERROR/Database(535):     at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:158)
02-14 15:59:34.642: ERROR/Database(535):     at com.connect.Test.getEvents(Connect_EY.java:755)
02-14 15:59:34.642: ERROR/Database(535):     at com.connect.Test.onCreate(Connect_EY.java:662)
02-14 15:59:34.642: ERROR/Database(535):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
02-14 15:59:34.642: ERROR/Database(535):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
02-14 15:59:34.642: ERROR/Database(535):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
02-14 15:59:34.642: ERROR/Database(535):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
02-14 15:59:34.642: ERROR/Database(535):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
02-14 15:59:34.642: ERROR/Database(535):     at android.os.Handler.dispatchMessage(Handler.java:99)
02-14 15:59:34.642: ERROR/Database(535):     at android.os.Looper.loop(Looper.java:123)

在此 getEvents 行上引发异常：

public class Test extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.pageview);

    startRefreshActivity();
    try { /* If No Record Exists Create a New One */
    eventsData = new EventDataSQLHelper(this);
    Cursor cursor = getEvents();
    startManagingCursor(cursor);

    } 
}

private Cursor getEvents() {
    try {
        db = eventsData.getReadableDatabase();
        Cursor cursor = db.query(EventDataSQLHelper.TABLE, null, null,
            null, null, null, null);
        startManagingCursor(cursor);
        return cursor;
    } catch (Exception ex) {
        System.out.println("Exception Occured : " + ex.toString());
        return null;
    }
}

例外：

02-14 15:59:34.642: ERROR/Database(535):     at com.testconnect.Test.getEvents(Test.java:755)
02-14 15:59:34.642: ERROR/Database(535):     at com.testconnect.Test.onCreate(Test.java:662)

【问题讨论】：

尝试在 onStop() 处关闭光标；试试这个 if(db!=null){ db = eventsData.getReadableDatabase(); }
@Vamsi 我试过了，但是那里抛出了空指针异常
你为 SQLiteOpenHelper 类实现了 onCreate() 和 onUpgrade() 吗？
@Vamsi 我已经实现了@Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 和 @Override public void onCreate(SQLiteDatabase db) { 在我的公共类 EventDataSQLHelper 扩展 SQLiteOpenHelper {

标签： android sqlite android-cursor

【解决方案1】：

我解决了异常。我在打电话

 db = eventsData.getReadableDatabase();

这就是抛出异常的两倍

【讨论】：

【解决方案2】：

你试过了吗：

     Cursor cursor = getEvents();
     startManagingCursor(cursor);
     cursor.close();

【讨论】：

我已经这样做了.. 但仍然显示异常。它显示在行 Cursor cursor = getEvents();在 getEvents 方法中 db = eventsData.getReadableDatabase();光标 cursor = db.query(EventDataSQLHelper.TABLE, null, null, null, null, null, null);在 Logcat 中，在这些行中抛出异常
我也面临这个应用程序没有关闭在此处打开的游标或数据库对象：问题..如何解决..请帮助

【解决方案3】：

你有没有试过像cursor.close这样在传递返回值后关闭光标

  private Cursor getEvents() {
     try {
            db = eventsData.getReadableDatabase();
            Cursor cursor = db.query(EventDataSQLHelper.TABLE, null, null,
             null, null, null, null);
            startManagingCursor(cursor);
            cursor.close();
            return cursor;

         } catch (Exception ex) {
              System.out.println("Exception Occured : " + ex.toString());
              return null;
      }

【讨论】：