CODEWITHSUNDEEP
javaandroidexceptionnull
mariozski
mariozski

Reputation: 1134

try catch exception always returns null

I got problem with Android. I develop on device and have problem with catching exceptions. I'm running some code in AsyncTask and finally simplified it to:

try
{
    if (true)
        throw new Exception("ERROR"); 
}      
catch (Exception e)
{    
    Log.e("e", "exception", e);
}

My problem is that 'e' variable is always null. Not sure what's happening actually. What's more it sometimes works, but I can't say when. I just get up from computer for few minutes come back and boom, it works. Doing coding few minutes and again it's null... There was one question on SO about 1 year ago but noone known answer. Maybe this time someone will have some idea.

Null exception

I think that it have something to do with AsyncTask as outside of it, I got exception catched properly... still don't have any clue why :( I found it only happens when debbuger is connected. When I take out cable from device it actually catches and exception isn't null anymore...

Upvotes: 14

Views: 12990

Answers (4)

ibanezshredd
ibanezshredd

Reputation: 48

I had this same problem.... I found it was the debugger like the other people had said. So what I did to debug is to just put the break point on the first line of the catch block, rather than right on the catch block. Seemed to work for me!

Upvotes: 2

Vitor M. Barbosa
Vitor M. Barbosa

Reputation: 3646

I know this is an old question, but this happened with me as well, and it seems like the problem is with the debugger itself!
When I run my app from eclipse (ctrl + F11), it catches a proper exception (e != null).

Upvotes: 2

yonojoy
yonojoy

Reputation: 5566

I had exactly the same strange problem inside an AsyncTask, while debugging on a real device (Galaxy Tab 2). (And yes, I got "e is really null!!!" doing the test suggested by @italo)

For me the problem mysteriously went away after unplugging the usb plug of the android device and connecting it again afterwards (and then running my app again).

Another suggestion, cleaning and rebuilding the project, as explained here didn't solve it for me (but maybe for somebody else).

Upvotes: 1

Italo Borssatto
Italo Borssatto

Reputation: 15689

It's impossible to have e with null value at that point. If you are debugging your app using Eclipse, it will show the e.toString() value at that point and the e.toString() is returning null.

Try another test, using this code:

try {
    if (true) {
        throw new Exception("ERROR");
    } 
}      
catch (Exception e) {
    if (e == null) {
        Log.e("e", "e is really null!!!");
    }
    else {
        Log.e("e", "e is not null, toString is " + e + " and message is " + e.getMessage());
    }
}

Upvotes: 4

Related Questions