22 
public int getRecordsCount() {
        String countQuery = "SELECT  * FROM " + TABLE_LOGIN;

        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery, null);
        if(cursor != null && !cursor.isClosed()){
            cursor.close();
        }   
        // return count

        return cursor.getCount();
    }

我正在尝试获取数据库中的记录总数，但是每次使用java.lang.IllegalStateException: attempt to re-open an already-closed object: android.database.sqlite.SQLiteQuery (mSql = SELECT * FROM login). 请帮我解决错误

  03-05 22:23:14.208: E/AndroidRuntime(4988): FATAL EXCEPTION: main
    03-05 22:23:14.208: E/AndroidRuntime(4988): java.lang.IllegalStateException: attempt to re-open an already-closed object: android.database.sqlite.SQLiteQuery (mSql = SELECT  * FROM login) 
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.database.sqlite.SQLiteClosable.acquireReference(SQLiteClosable.java:34)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.database.sqlite.SQLiteQuery.fillWindow(SQLiteQuery.java:64)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.database.sqlite.SQLiteCursor.fillWindow(SQLiteCursor.java:283)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.database.sqlite.SQLiteCursor.getCount(SQLiteCursor.java:264)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at com.ecomm.android.sqlite.DatabaseHandler.getRecordsCount(DatabaseHandler.java:123)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at com.ecomm.android.LaunchActivity.DataBaseImplementation(LaunchActivity.java:120)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at com.ecomm.android.LaunchActivity.onClick(LaunchActivity.java:98)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.view.View.performClick(View.java:2408)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.view.View$PerformClick.run(View.java:8816)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.os.Handler.handleCallback(Handler.java:587)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.os.Handler.dispatchMessage(Handler.java:92)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.os.Looper.loop(Looper.java:123)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at android.app.ActivityThread.main(ActivityThread.java:4627)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at java.lang.reflect.Method.invokeNative(Native Method)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at java.lang.reflect.Method.invoke(Method.java:521)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:876)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:634)
    03-05 22:23:14.208: E/AndroidRuntime(4988):     at dalvik.system.NativeStart.main(Native Method)
    03-05 22:23:15.608: I/binder_sample(4988): [android.app.IActivityManager,2,1395,com.ecomm.android,100]
    03-05 22:23:15.608: I/binder_sample(4988): Unknown binary event type 110
    03-05 22:23:15.608: I/binder_sample(4988): Binary log entry conversion failed
4

5 回答 5

29

您应该getCount()在关闭光标之前调用。

移动：

if(cursor != null && !cursor.isClosed()){
    cursor.close();
}

以下：

 cursor.getCount();

像这样：

public int getRecordsCount() {
    int count = 0;
    String countQuery = "SELECT  * FROM " + TABLE_LOGIN;

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(countQuery, null);



    if(cursor != null && !cursor.isClosed()){
        count = cursor.getCount();
        cursor.close();
    }   
    return count;
}
于 2013-03-11T12:20:06.807 回答
5

java.lang.IllegalStateException：尝试重新打开已经关闭的

您的错误被抛出，因为您调用cursor.getCount()您Cursor已经关闭并且这是不允许的。

因此，要么尝试使用try-finally块，在 finally 块中关闭你的块，Cursor要么分配cursor.getCount()给 int 值并Cursor立即关闭。

但我建议您使用第一种方法：

public int getRecordsCount() {
   String countQuery = "SELECT * FROM " + TABLE_LOGIN;
   SQLiteDatabase db = this.getReadableDatabase();
   Cursor cursor = db.rawQuery(countQuery, null);
   int count = 0;
   try {
      if (cursor.moveToFirst())) {
         count = cursor.getCount();
      }
      return count;
   }
   finally {
      if (cursor != null) {
         cursor.close();
      }
   }
}
于 2013-03-11T12:26:01.227 回答
2

删除cursor.close()语句

于 2016-07-13T17:29:13.343 回答
1

我知道这是旧的，但我的问题最终是在，我在执行后onCreate()调用。db.close()db.execSQL(TABLE_CREATE)

onCreate之后自动调用dbHelper.getReadableDatabase()。

这导致它崩溃，因为随后它使用已经关闭的对象从数据库中检索所有值。一旦我db.close()从中删除onCreate，这一切都奏效了。

于 2015-05-27T12:34:50.597 回答
0

对我来说，问题是我正在关闭更新查询的 finally 块中的数据库实例。

对于无法使用上述解决方案进行修复的人，请尝试检查您的更新查询。

于 2020-07-20T13:03:49.447 回答