Probably by opening the db both in onCreate() and onResume() in some
circustances (e.g. first execution of your app) the db will be opened twice,
which for sure is not good.
If you open the db only in onResume() it should be fine (although I didn't
try it by myself). Usually, when I need data from the db, I call db.open(),
fetch my data, and db.close(). In this way I'm pretty sure there won't be
any such leak. Still I don't know if that's "the best way" to do it.
YuviDroid
On Thu, Jul 15, 2010 at 3:51 PM, Bender<abende...@googlemail.com> wrote:
Hi,
I'm writing an app which has 2 activities and gets his data from a
database. Unfortunately I'm not sure when I have to open and close the
database properly. In both activities I'm opening the database so the
activities can access its data. When I do the following:
* Start the app
* Open activity 1
* Open activity 2 (via button in activity 1)
* Hit the back button (back to activity 1)
* Again back button (back to home screen)
* Start the app
I'm receiving such an leak error:
07-15 14:34:19.504: ERROR/Database(234): Leak found
07-15 14:34:19.504: ERROR/Database(234):
java.lang.IllegalStateException: mPrograms size 1
07-15 14:34:19.504: ERROR/Database(234): at
android.database.sqlite.SQLiteDatabase.finalize(SQLiteDatabase.java:
1669)
07-15 14:34:19.504: ERROR/Database(234): at
dalvik.system.NativeStart.run(Native Method)
07-15 14:34:19.504: ERROR/Database(234): Caused by:
java.lang.IllegalStateException: /data/data/de.anote/databases/
anote.db SQLiteDatabase created and never closed
.... more stuff .....
I guess it is because I'm not closing the database so implemented the
following:
* db.open() in both onCreate() and both onResume() methods by the 2
activities
* db.close() in both onPause() methods.
But now I'm receiving another error:
07-15 15:27:18.472: ERROR/AndroidRuntime(266): Uncaught handler:
thread main exiting due to uncaught exception
07-15 15:27:18.508: ERROR/AndroidRuntime(266):
java.lang.RuntimeException: Unable to resume activity {de.anote/
de.anote.gui.CategoryView}: java.lang.IllegalStateException: mQuery
SELECT _id, note_name, value, date, category, priority, reminderbool,
reminder, todo FROM t_note WHERE category=? ORDER BY date 1
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.app.ActivityThread.performResumeActivity(ActivityThread.java:
2950)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.app.ActivityThread.handleResumeActivity(ActivityThread.java:
2965)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.app.ActivityThread$H.handleMessage(ActivityThread.java:1889)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.os.Handler.dispatchMessage(Handler.java:99)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.os.Looper.loop(Looper.java:123)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.app.ActivityThread.main(ActivityThread.java:4363)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
java.lang.reflect.Method.invokeNative(Native Method)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
java.lang.reflect.Method.invoke(Method.java:521)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
com.android.internal.os.ZygoteInit
$MethodAndArgsCaller.run(ZygoteInit.java:860)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
dalvik.system.NativeStart.main(Native Method)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): Caused by:
java.lang.IllegalStateException: mQuery SELECT _id, note_name, value,
date, category, priority, reminderbool, reminder, todo FROM t_note
WHERE category=? ORDER BY date 1
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.database.sqlite.SQLiteQuery.requery(SQLiteQuery.java:162)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.database.sqlite.SQLiteCursor.requery(SQLiteCursor.java:536)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.app.Activity.performRestart(Activity.java:3736)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.app.Activity.performResume(Activity.java:3756)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.app.ActivityThread.performResumeActivity(ActivityThread.java:
2937)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): ... 10 more
07-15 15:27:18.508: ERROR/AndroidRuntime(266): Caused by:
android.database.sqlite.SQLiteMisuseException: library routine called
out of sequence: handle 0x0
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.database.sqlite.SQLiteProgram.native_bind_string(Native
Method)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.database.sqlite.SQLiteProgram.bindString(SQLiteProgram.java:
178)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): at
android.database.sqlite.SQLiteQuery.requery(SQLiteQuery.java:153)
07-15 15:27:18.508: ERROR/AndroidRuntime(266): ... 14 more
Unfortunately I can't read which line in my code causes this exception
but I guess it is because there is some point where is a database
access and the db is still closed.
So my question is, at which places should I open and close my
database? It is right to open it in the onCreate(), onResume() methods
and close it in onPause()?
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