[android-developers] Re: Sqlite Error

indeed -- i did investigate moving to this pattern, but i found that
putting the assignment inside the try() allowed me to change my mind
about having a catch() clause too with no other code changes inside
the method.

i have wrappers for common items that are closable, such as streams,
readers/writers, cursors, etc, which check for null and swallow any
exceptions, so it's only one line inside the finally().

quite why stream.close() throws IOException is kinda beyond me though :-)

>Good advice -- always be on the lookout for cleanup that can be done
>in a finally, even if you don't see it as strictly necessary!
>
>Actually, you can usually simplify this slightly:
>
>Cursor c = ...;
>try {
> dostuff(c); // Do something with the cursor
>} finally {
> c.close();
>}
>
>There's no timing window or anything here. The variable 'c' won't be
>assigned unless there's a successful return of a cursor, and there's
>no opportunity for a throw between that and the operations on the
>cursor.
>
>Separating the assignment and moving it into the try body does require
>that you test for null in the finally clause. Occasionally it's worth
>the extra hassle, so you can combine the finally with another try/
>catch -- but usually it's better to simply use a separate try/catch
>for each. In C++, assignments can generate exceptions, so doing the
>assignment within the try is a good habit, and sometimes essential. In
>Java, this is not a concern, so we can optimize for making it as easy
>as possible to write and read the code, and thus encouraging liberal
>use of the pattern!
>
>BTW, try/catch are not expensive in the non-throw case. It generates
>static code ranges that are looked up during handling throw, and
>doesn't involve any extra execution steps if no throw is done. So
>always just try for the cleanest code.
>
>On Feb 8, 10:12 am, Jason Proctor <jason.android.li...@gmail.com>
>wrote:
>> well, like the error says, the cursor is being garbage collected but
>> it hadn't been closed or deactivated.
>>
>> you must close your cursors!
>>
>> and do it in a finally block so that they still get closed even if
>> other code throws an exception.
>>
>> for example --
>>
>> Cursor c = null;
>>
>> try
>> {
>> c = resolver.query (...);
>>
>> // ...run through the query}
>>
>> finally
>> {
>> if (c != null)
>> {
>> c.close ();
>> }
>>
>> }
>>
>> not exactly like this, but you get the idea.
>>
>> hth
>> J
>>
>>
>>
>>
>>
>> >Hi,
>>
>> >In my program i'm using sqlite database.
>>
>> >After using that Sqlite program when i'm using some other layout it
>> >is showing the below exception.
>>
>> >02-06 14:17:59.320: INFO/dalvikvm(853): Uncaught exception thrown by
>> >finalizer (will be discarded):
>> >02-06 14:17:59.371: INFO/dalvikvm(853):
>> >Ljava/lang/IllegalStateException;: Finalizing cursor
>> >android.database.sqlite.SQLiteCursor@43c4e358 on DB1 that has not
>> >been deactivated or closed
>> >02-06 14:17:59.729: INFO/dalvikvm(853): at
>> >android.database.sqlite.SQLiteCursor.finalize(SQLiteCursor.java:596)
>> >02-06 14:17:59.800: INFO/dalvikvm(853): at
>> >dalvik.system.NativeStart.run(Native Method)
>> >02-06 14:17:59.878: INFO/dalvikvm(853): Uncaught exception thrown by
>> >finalizer (will be discarded):
>> >02-06 14:17:59.900: INFO/dalvikvm(853):
>> >Ljava/lang/IllegalStateException;: Finalizing cursor
>> >android.database.sqlite.SQLiteCursor@43b9cf30 on DB2 that has not
>> >been deactivated or closed
>> >02-06 14:17:59.909: INFO/dalvikvm(853): at
>> >android.database.sqlite.SQLiteCursor.finalize(SQLiteCursor.java:596)
>> >02-06 14:17:59.919: INFO/dalvikvm(853): at
>> >dalvik.system.NativeStart.run(Native Method)
>> >02-06 14:17:59.968: INFO/dalvikvm(853): Uncaught exception thrown by
>> >finalizer (will be discarded):
>> >02-06 14:17:59.989: INFO/dalvikvm(853):
>> >Ljava/lang/IllegalStateException;: Finalizing cursor
>> >android.database.sqlite.SQLiteCursor@43b9c5e8 on null that has not
>> >been deactivated or closed
>> >02-06 14:18:00.049: INFO/dalvikvm(853): at
> > >android.database.sqlite.SQLiteCursor.finalize(SQLiteCursor.java:596)
>> >02-06 14:18:00.049: INFO/dalvikvm(853): at
>> >dalvik.system.NativeStart.run(Native Method)
>> >02-06 14:18:00.088: INFO/dalvikvm(853): Uncaught exception thrown by
>> >finalizer (will be discarded):
>> >02-06 14:18:00.109: INFO/dalvikvm(853):
>> >Ljava/lang/IllegalStateException;: Finalizing cursor
>> >android.database.sqlite.SQLiteCursor@43b95fc8 on null that has not
>> >been deactivated or closed
>> >02-06 14:18:00.119: INFO/dalvikvm(853): at
>> >android.database.sqlite.SQLiteCursor.finalize(SQLiteCursor.java:596)
>> >02-06 14:18:00.140: INFO/dalvikvm(853): at
>> >dalvik.system.NativeStart.run(Native Method)
>>
>> >wat's this?..
>> >how to over come this?
>> >any one can explain me?..
>>
>> >--
>> >Thanks & Regards
>> >Sasikumar.S
>>
>> >--
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>>
>> --
>> jason.vp.engineering.particle
>
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