关于CursorWindowAllocatoinException的SO有很多问题:
- SQLite Android 数据库光标窗口分配 2048 kb 失败
- 无法分配 CursorWindow
- 分配游标时内存不足
- Android SQLite CursorWindowAllocationException 崩溃
他们都建议游标在使用后必须关闭。但这并没有解决我的问题。这是我的代码:
String query = "select serial from tbl1 union select serial from tbl2 union select serial from tbl3";
SQLiteDatabase db = null;
Cursor cur = null;
try {
SettingsDatabaseHelper dal = new SettingsDatabaseHelper(
c);
db = dal.getReadableDatabase();
cur = db.rawQuery(query, null);
int numRows = cur.getCount();
if (numRows > 0) {
cur.moveToFirst();
int serialIdx = cur.getColumnIndexOrThrow("serial");
for (boolean hasItem = cur.moveToFirst(); hasItem; hasItem = cur
.moveToNext()) {
String serial = cur.getString(serialIdx);
if (Validator.getInstance().isValidSerial(serial))
serials.add(serial);
}
}
} finally {
if (cur != null)
cur.close();
if (db != null)
db.close();
}
我每隔几秒钟运行一次这个方法。半小时后,我进去CursorWindowAllocationException
了int numRows=cur.getCount();
,然后我的服务停止了。
由于我正在关闭光标,因此我的 Helper 类可能存在问题。这是代码:
public class SettingsDatabaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "mydb.db";
private static final int DATABASE_VERSION = 1;
private static final String TBL_CREATE="create table...";
public SettingsDatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase database) {
database.execSQL(TBL_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
onCreate(db);
}
}
如何防止抛出此异常?