Handling Runtime exception in Java

Question

I have the following piece of code

 try{//do something
     }
  catch (Exception e) {
        log.error(e, e);
        if (e instanceof RuntimeException) {
            throw (RuntimeException) e;
        } else {
            throw new RuntimeException(e);
        }
    }

the findbugs stataic analysis tool throws this warning on it

instanceof will always return true for all nonnull values in methodX, since all RuntimeException are instances of RuntimeException

what i dont understand is that its Exception which is being caught and not the RuntimeException, so why this warning ?

score 6 · Answer 1 · answered May 23 '12 at 10:00

6

Perhaps, the // do something code does not throw any checked exception, so the only exceptions you can get in your try-block are unchecked ones (subclassing RuntimeException).

answered May 23 '12 at 10:00

Alexander Pavlov

31,598
5
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score 4 · Accepted Answer · answered May 23 '12 at 10:08

4

You could also try following code. This will be better to read and maintain.

try{//do something
}
catch (RuntimeException e) {
    throw e;
} 
catch (Exception e) {
    throw new RuntimeException(e);
}

answered May 23 '12 at 10:08

Daniel Engmann

2,840
1
23
17

score 2 · Answer 3 · answered May 23 '12 at 10:04

2

Probably there is no methods that throws not RuntimeException in "try" part. Therefore, you can use construction

catch(RuntimeException e)
{
 //Do something
}

answered May 23 '12 at 10:04

anstarovoyt

7,956
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score 0 · Answer 4 · answered Oct 03 '12 at 15:18

Try http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/base/Throwables.html#propagate%28java.lang.Throwable%29. It does exactly what you want. Today I did the replacement for the same reason (findbugs warning), also looked the source of this method.

Handling Runtime exception in Java

4 Answers4

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