异步任务期间的游标异常

Question

我是运行一个后台任务，它会下载一个 JSON 文件，解析它，然后将它添加到 SQLite 数据库的内容中。

我在运行时遇到了一些错误。

Caused by: android.database.CursorWindowAllocationException: Cursor window allocation of 2048 kb failed. # Open Cursors=728 (# cursors opened by this proc=728)

E/CursorWindow: Could not allocate CursorWindow '/data/data/com.mycompany.inventory/databases/dbInventory.sql' of size 2097152 due to error -12.

JSON 中有大约 1500 个项目。

这是我的异步任务调用的方法：

public void addModelsToDB(JSONObject dict){
        String  insertQuery  = "";
        String  deleteQuery  = "DROP TABLE IF EXISTS 'tblModels'";
        String  createQuery  = "CREATE TABLE 'tblModels' ('modelsID' INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,'makeKey' INTEGER, 'modelName' TEXT, 'modelKey' INTEGER)";

        Cursor cursor = dbLocals.executeRawQuery(deleteQuery, null);
        cursor.moveToFirst();
        cursor = dbLocals.executeRawQuery(createQuery, null);
        cursor.moveToFirst();

        try {
            JSONArray dicRecordSet  = dict.getJSONArray("Recordset");
            JSONObject dicRecords = dicRecordSet.getJSONObject(0);
            JSONArray arrRecords = dicRecords.getJSONArray("Record");


            for (int i = 0; i < arrRecords.length(); i++) {
                JSONObject record = arrRecords.getJSONObject(i);
                insertQuery = "INSERT INTO 'tblModels' VALUES(" + null +  ", "
                        + record.getString("MODMAKlMakeKey") + ", '"
                        + record.getString("MODvc50Name").replaceAll("'", "''") + "', "
                        + record.getString("MODlModelKey")
                        +")";
                cursor =  dbLocals.executeRawQuery(insertQuery, null);
                cursor.moveToFirst();
            }

        } catch (JSONException e) {
            e.printStackTrace();
        }

        cursor.close();
    }

我的数据库一个管理器returns一个游标。

public Cursor executeRawQuery(String query, String[] selectionArgs) {
        Cursor cursor = databaseConn.rawQuery(query, selectionArgs);
        return cursor;
    }

我做错了什么？

Answer 1

您应该在使用后关闭游标。在循环内部，您在每次迭代中都创建了一个游标，而没有关闭它。显然，打开游标的数量是有限制的，而您达到了该限制。

Answer 2

您不能重复使用游标变量，因为它覆盖了原来的变量，因此您不能关闭它：

Cursor cursor = dbLocals.executeRawQuery(deleteQuery, null);

然后

cursor =  dbLocals.executeRawQuery(insertQuery, null);

第二个赋值意味着您无法关闭原始游标。

此外，您为什么要在此处创建 table？

编辑：

这样使用：

public void addModelsToDB(JSONObject dict){
    String  insertQuery  = "";
    String  deleteQuery  = "DROP TABLE IF EXISTS 'tblModels'";
    String  createQuery  = "CREATE TABLE 'tblModels' ('modelsID' INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,'makeKey' INTEGER, 'modelName' TEXT, 'modelKey' INTEGER)";

    Cursor cursor = dbLocals.executeRawQuery(deleteQuery, null);
    try {
        cursor.moveToFirst();
        cursor = dbLocals.executeRawQuery(createQuery, null);
        cursor.moveToFirst();
    } finally {
        cursor.close();
    }

    try {
        JSONArray dicRecordSet  = dict.getJSONArray("Recordset");
        JSONObject dicRecords = dicRecordSet.getJSONObject(0);
        JSONArray arrRecords = dicRecords.getJSONArray("Record");


        for (int i = 0; i < arrRecords.length(); i++) {
            JSONObject record = arrRecords.getJSONObject(i);
            insertQuery = "INSERT INTO 'tblModels' VALUES(" + null +  ", "
                    + record.getString("MODMAKlMakeKey") + ", '"
                    + record.getString("MODvc50Name").replaceAll("'", "''") + "', "
                    + record.getString("MODlModelKey")
                    +")";
            cursor =  dbLocals.executeRawQuery(insertQuery, null);
            try {
                cursor.moveToFirst();
            } finally {
                cursor.close();
            }
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }
}

异步任务期间的游标异常

Cursor Exception during Async Task

sqlite

android

json

cursor