Thank U for all...
On Tue, Feb 9, 2010 at 7:18 AM, Jason Proctor <[email protected]
> wrote:
> 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 <[email protected]>
>> 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.sqlitecur...@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.sqlitecur...@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.sqlitecur...@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.sqlitecur...@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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>
>
> --
> jason.vp.engineering.particle
>
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--
Thanks & Regards
Sasikumar.S
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