Question

所以我刚刚完成了我已经工作了一段时间的应用程序上的所有内容。我在控制台中遇到的唯一错误是DatabaseObjectNotClosedException。它不会导致应用程序关闭或崩溃或任何事情，但我担心这一点，因为我已经读过一个未封闭的游标可能是一个大问题。

所以这是错误信息：

05-28 20：40：01.598：E / Database（655）：android.database.sqlite.DatabaseObjectNotClosedException：应用程序未关闭此处打开的游标或数据库对象

以下是它所指的代码：

    datasource = new ProgressDataSource(this);
    datasource.open();

以下是ProgressDataSource的代码：

package com.gauv.myapp;

import java.util.Arrays;
import java.util.Collections;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import com.jjoe64.graphview.GraphView.GraphViewData;

public class ProgressDataSource {

    private SQLiteDatabase database;
    private MySQLiteHelper dbHelper;

    public ProgressDataSource(Context context) {
        dbHelper = new MySQLiteHelper(context);
    }

    public void open() throws SQLException {
        database = dbHelper.getWritableDatabase();
    }

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

    public GraphViewData[] fetchProgress(long dayExerciseDataID) {      
        Cursor cursor = database.rawQuery("select " + MySQLiteHelper.COLUMN_1RM + " " +
                "from " + MySQLiteHelper.TABLE_LOGS + " " +
                "where " + MySQLiteHelper.COLUMN_ID_DAY_EXERCISE + "='" + dayExerciseDataID + "' " +
                "order by " + MySQLiteHelper.COLUMN_DATE + " desc limit 30", null);

        GraphViewData[] data = new GraphViewData[cursor.getCount()];
        Long[] onerms = new Long[cursor.getCount()];

        int i = 0;

        cursor.moveToFirst();
        while (cursor.isAfterLast() == false) 
        {
            onerms[i] = cursor.getLong(0);
            i++;
            cursor.moveToNext();
        }

        Collections.reverse(Arrays.asList(onerms));

        int y = 1;

        for (int x = 0; x < onerms.length; x++) {
            data[x] = new GraphViewData(y, onerms[x]);
            y++;
        }

        return data;
    }

    public String fetchProgressCount(long dayExerciseDataID) {
        Cursor cursor = database.rawQuery("select " + MySQLiteHelper.COLUMN_1RM + " " +
                "from " + MySQLiteHelper.TABLE_LOGS + " " +
                "where " + MySQLiteHelper.COLUMN_ID_DAY_EXERCISE + "='" + dayExerciseDataID + "' " +
                "order by " + MySQLiteHelper.COLUMN_DATE + " desc limit 12", null);

        return String.valueOf(cursor.getCount());
    }
}

我只需要将cursor.close()添加到fetchProgress函数吗？

Answer 1

完成后你需要关闭你的数据库所以你需要做的就是调用datasource.close()，是的你也应该关闭你不再使用的任何游标来从内存中释放它

Answer 2

此错误表示您打开了数据库连接。您的代码段确认了这一点。一个好的做法是将光标中的信息导入某个域对象，然后清理光标和连接。

代码示例：

// open db connection
DataBaseHelper db = new DataBaseHelper(this);
db.open();

// retrieve your items using a cursor object
Cursor cursor = db.rawQuery("SELECT * FROM SOME_DB", null); 

// iterate all your items here and move to some collection or domain model 
// ...

// and clean up your mess
cursor.close();
db.close();

控制台中的DatabaseObjectNotClosedException

2 个答案: