Issue
I am using Cursor to get data from DB (it's information about the overlay markers on Map). I am loading a map with help of this data. Interaction with the DB through Cursor is done in a asyncTask.
Now here is the problem I am facing. If I press back button while the cursor is running to load the map (i.e. in middle of loading overlay markers in a while loop) I get this error:
Caused by: java.lang.IllegalStateException: attempt to re-open an already-closed object: android.database.sqlite.SQLiteQuery (mSql = SELECT _id, category, latitude, longitude FROM node)
Here is the complete trace of it:
12-21 11:11:30.173: E/AndroidRuntime(2824): FATAL EXCEPTION: AsyncTask #5
12-21 11:11:30.173: E/AndroidRuntime(2824): java.lang.RuntimeException: An error occured while executing doInBackground()
12-21 11:11:30.173: E/AndroidRuntime(2824): at android.os.AsyncTask$3.done(AsyncTask.java:200)
12-21 11:11:30.173: E/AndroidRuntime(2824): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
12-21 11:11:30.173: E/AndroidRuntime(2824): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
12-21 11:11:30.173: E/AndroidRuntime(2824): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
12-21 11:11:30.173: E/AndroidRuntime(2824): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
12-21 11:11:30.173: E/AndroidRuntime(2824): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
12-21 11:11:30.173: E/AndroidRuntime(2824): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
12-21 11:11:30.173: E/AndroidRuntime(2824): at java.lang.Thread.run(Thread.java:1102)
12-21 11:11:30.173: E/AndroidRuntime(2824): Caused by: java.lang.IllegalStateException: attempt to re-open an already-closed object: android.database.sqlite.SQLiteQuery (mSql = SELECT _id, category, latitude, longitude FROM node)
12-21 11:11:30.173: E/AndroidRuntime(2824): at android.database.sqlite.SQLiteClosable.acquireReference(SQLiteClosable.java:34)
12-21 11:11:30.173: E/AndroidRuntime(2824): at android.database.sqlite.SQLiteQuery.fillWindow(SQLiteQuery.java:64)
12-21 11:11:30.173: E/AndroidRuntime(2824): at android.database.sqlite.SQLiteCursor.fillWindow(SQLiteCursor.java:299)
12-21 11:11:30.173: E/AndroidRuntime(2824): at android.database.sqlite.SQLiteCursor.onMove(SQLiteCursor.java:271)
12-21 11:11:30.173: E/AndroidRuntime(2824): at android.database.AbstractCursor.moveToPosition(AbstractCursor.java:188)
12-21 11:11:30.173: E/AndroidRuntime(2824): at android.database.AbstractCursor.moveToNext(AbstractCursor.java:256)
12-21 11:11:30.173: E/AndroidRuntime(2824): at org.mid.kew.activities.MapPageActivity$MapLoadingAsyncTask.doInBackground(MapPageActivity.java:632)
12-21 11:11:30.173: E/AndroidRuntime(2824): at org.mid.kew.activities.MapPageActivity$MapLoadingAsyncTask.doInBackground(MapPageActivity.java:1)
12-21 11:11:30.173: E/AndroidRuntime(2824): at android.os.AsyncTask$2.call(AsyncTask.java:185)
12-21 11:11:30.173: E/AndroidRuntime(2824): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
12-21 11:11:30.173: E/AndroidRuntime(2824): ... 4 more
and here is a snapshot of code I am using in asyncTask
Under DoInBackground method
openKewDataBase();
Cursor cursor = getCursorForOverLayIcons();
startManagingCursor(cursor);
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
...
cursor.moveToNext();
}
cursor.close();
Under onPostExecute Method
....
closeKewDataBase();
As per I can trace Its crashing at "cursor.moveToNext();"
Solution
As you are manually closing the cursor with cursor.close()
, you shouldn't call startManagingCursor(cursor)
. You need to choose one or the other.
As you are doing this in an AsyncTask
, you almost certainly don't want the enclosing Activity
to manage the cursor for you, as the AsyncTask
can outlive the Activity
. So just do it manually.
(I presume the AsyncTask
is an inner class of your Activity
.)
Answered By - Graham Borland
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