catching null exception

Question

I'm working on a java application for android and I currently am getting a problem where the debugger is stepping into my catch block and somehow ex is null? Has anyone seen anything like this before?

}
catch(Exception ex)
{
   // Debugger is coming through the catch block and ex is null ????
}

score 6 · Accepted Answer · answered Oct 13 '11 at 14:38

6

This sounds like the source code and the compiled classes are out of sync, so the debugger is stepping into the wrong block.

Try to do a clean and then a rebuild.

answered Oct 13 '11 at 14:38

Michael Krussel

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I cleaned the project and rebuilt, seems fixed. Thanks! – David Carpenter Oct 13 '11 at 14:44

score 1 · Answer 2 · answered Oct 13 '11 at 14:12

1

The exception will never be null in that block. If the instruction pointer in the debugger is pointing at the catch line, you need to step one more line to get the exception to be accessible to you. You may want to add a line of code (potentially a log call) to your catch block and put your break point on that to catch what ex is.

answered Oct 13 '11 at 14:12

Justin Breitfeller

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Yep, I even tried `throw null;` but then an instance `NullPointerException` is caught. – Ben van Gompel Oct 13 '11 at 14:16
If you are saying I answered your question, then please click the checkbox next to my answer saying I solved your issue. – Justin Breitfeller Oct 13 '11 at 14:36
I was not the one who asked the question, so I cannot do that. – Ben van Gompel Oct 13 '11 at 14:39
Sorry Ben.... didn't even realize you weren't the original poster. Must be out of my mind today. – Justin Breitfeller Oct 13 '11 at 14:57
No worries. I think your answer is correct though ;-) – Ben van Gompel Oct 14 '11 at 06:47

score 0 · Answer 3 · answered Feb 05 '14 at 09:30

I had exactly the same problem inside an AsyncTask, while debugging on a real device (Galaxy Tab 2). So I too can confirm, that this strange problem is real.

For me the accepted answer didn't help.

But in my case the problem mysteriously went away after unplugging the usb plug of the device and connecting it again afterwards (and then running my app again).

score 0 · Answer 4 · answered Oct 13 '11 at 14:14

0

Add some log statements and check. Your ex may be out of scope.

answered Oct 13 '11 at 14:14

Vaandu

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David Carpenter in question says "// Debugger is coming through the catch block and ex is null ????". So "ex" is in scope. – hasanghaforian May 19 '15 at 03:00

catching null exception

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