android - 陈旧数据异常 : Attempted to access a cursor after it has been closed

Question

FATAL EXCEPTION: main
Process: com.example.lenovo.phone, PID: 4885
android.database.StaleDataException: Attempted to access a cursor after it has been closed.
at android.database.BulkCursorToCursorAdaptor.throwIfCursorIsClosed(BulkCursorToCursorAdaptor.java:64)
at android.database.BulkCursorToCursorAdaptor.requery(BulkCursorToCursorAdaptor.java:133)
at android.database.CursorWrapper.requery(CursorWrapper.java:186)
at android.app.Activity.performRestart(Activity.java:5309)
at android.app.ActivityThread.handleSleeping(ActivityThread.java:3514)
at android.app.ActivityThread.access$2900(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1500)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5299)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)                                                                               
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:829)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:645)
at dalvik.system.NativeStart.main(Native Method)

Answer 1

删除这个:

protected SQLiteDatabase database;

本地化

基本上 2 个方法同时执行，一个方法称为 database.close()，而第二个方法仍在访问数据，因此 Exception

使用这个:

public class db {

DataBaseHelper dbHelper;
Context mContext;


public db(Context context) {
    this.mContext = context;
}

public db open() throws SQLException {
    dbHelper = new DataBaseHelper(mContext);
    return this;
}


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

public void insertdb( int id,String ph_num, String call_type, String calldate, String call_duration, String upload_status) {
    SQLiteDatabase database = dbHelper.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put(DataBaseHelper.id,id);
    values.put(DataBaseHelper.phone_number, ph_num);
    values.put(DataBaseHelper.call_type, call_type);
    values.put(DataBaseHelper.call_date, calldate);
    values.put(DataBaseHelper.call_duration, call_duration);
    values.put(DataBaseHelper.upload_status, upload_status);
    database.insert(DataBaseHelper.table_name, null, values);
    database.close();
    // Log.d("Database helper", "values inserted");
}


public ArrayList<HashMap<String, String>> getAllUsers() {
    ArrayList<HashMap<String, String>> wordList;
    wordList = new ArrayList<HashMap<String, String>>();
    String selectQuery = "SELECT  * FROM call_logtable";
    SQLiteDatabase database = dbHelper.getWritableDatabase();
    Cursor cursor = database.rawQuery(selectQuery, null);
    if (cursor.moveToFirst()) {
        do {
            HashMap<String, String> map = new HashMap<String, String>();
            map.put("id", cursor.getString(0));
            map.put("phone_number", cursor.getString(1));
            map.put("call_type", cursor.getString(2));
            map.put("call_date", cursor.getString(3));
            map.put("call_duration", cursor.getString(4));
            wordList.add(map);
        } while (cursor.moveToNext());
    }
    cursor.close(); // just added
    database.close();
    return wordList;
}

/**
 * Compose JSON out of SQLite records
 * @return
 */
public String composeJSONfromSQLite(){
    ArrayList<HashMap<String, String>> wordList;
    wordList = new ArrayList<HashMap<String, String>>();
    String selectQuery = "SELECT  * FROM call_logtable where upload_status = '"+"no"+"'";
    SQLiteDatabase database = dbHelper.getWritableDatabase();
    Cursor cursor = database.rawQuery(selectQuery, null);
    if (cursor.moveToFirst()) {
        do {
            HashMap<String, String> map = new HashMap<String, String>();
            map.put("id", cursor.getString(0));
            map.put("phone_number", cursor.getString(1));
            map.put("call_type", cursor.getString(2));
            map.put("call_date", cursor.getString(3));
            map.put("call_duration", cursor.getString(4));
            wordList.add(map);
        } while (cursor.moveToNext());
    }
    cursor.close(); // just added
    database.close();
    Gson gson = new GsonBuilder().create();
    //Use GSON to serialize Array List to JSON
    return gson.toJson(wordList);
}


public int dbSyncCount(){
    int count = 0;
    String selectQuery = "SELECT  * FROM call_logtable where upload_status = '"+"no"+"'";
    SQLiteDatabase database = dbHelper.getWritableDatabase();
    Cursor cursor = database.rawQuery(selectQuery, null);
    count = cursor.getCount();
    cursor.close(); // just added
    database.close();
    return count;
}


public void updateSyncStatus(String id, String status){
    SQLiteDatabase database = dbHelper.getWritableDatabase();
    String updateQuery = "Update call_logtable set upload_status = '"+ status +"' where id="+"'"+ id +"'";
    Log.d("query", updateQuery);
    database.execSQL(updateQuery);
    database.close();
}

public Cursor getinformation()
{
    SQLiteDatabase database = dbHelper.getReadableDatabase();
    String[] columns={DataBaseHelper.phone_number,DataBaseHelper.call_type,DataBaseHelper.call_date,DataBaseHelper.call_duration,DataBaseHelper.upload_status};
    return database.query(DataBaseHelper.table_name,columns,null,null,null,null,null);
}

public void delete()
{
    SQLiteDatabase database = dbHelper.getWritableDatabase();
    // String[] columns={DataBaseHelper.phone_number,DataBaseHelper.call_type,DataBaseHelper.call_date,DataBaseHelper.call_duration};
    database.delete(DataBaseHelper.table_name, null, null);
}


StringBuffer readSpecificfrom_db(String type)
{
    String ph_number=null;
    String call_type=null;
    String call_date=null;
    String call_duration=null;
    String upload_status=null;
    StringBuffer sb = new StringBuffer();
    //sb.append("Call Log :");
    Cursor cursor_object=getinformation();
    cursor_object.moveToFirst();
    do {
        if((cursor_object.getString(1)).equals(type)) {
            ph_number = cursor_object.getString(0);
            call_type = cursor_object.getString(1);
            call_date = cursor_object.getString(2);
            call_duration = cursor_object.getString(3);
            if(type=="Missed") {
                sb.append("\nPhone Number:--- " + ph_number +
                                " \nCall Type:--- " + call_type +
                                " \nCall Date:--- " + call_date
                        //   + " \nCall duration in sec :--- " + call_duration
                );
                sb.append("\n----------------------------------");
            }
            else
            {
                sb.append("\nPhone Number:--- " + ph_number +
                        " \nCall Type:--- " + call_type +
                        " \nCall Date:--- " + call_date
                        + " \nCall duration in sec :--- " + call_duration);
                sb.append("\n----------------------------------");
            }
        }
    }while(cursor_object.moveToNext());
    cursor_object.close(); // just added
    return sb;

}

StringBuffer readfrom_db()
{
    String ph_number=null;
    String call_type=null;
    String call_date=null;
    String call_duration=null;
    String upload_status;
    //  int id=0;
    StringBuffer sb = new StringBuffer();
    // sb.append("Call Log :");
    Cursor cursor_object=getinformation();
    cursor_object.moveToFirst();
    do {
        ph_number=cursor_object.getString(0);
        call_type=cursor_object.getString(1);
        call_date=cursor_object.getString(2);
        call_duration=cursor_object.getString(3);
        sb.append("\nPhone Number:--- " + ph_number +
                " \nCall Type:--- " + call_type +
                " \nCall Date:--- " + call_date
                + " \nCall duration in sec :--- " + call_duration);
        sb.append("\n----------------------------------");

    } while(cursor_object.moveToNext());
    cursor_object.close(); // just added
    return sb;
}