Replace a checked exception with a runtime exception?

Question

Given that I basically want to eliminate checked exception usage and transform them to runtime exceptions, I would normally be doing something like this:

try {
    file.read();
} catch (IOException e){
    throw new RuntimeException(e); 
}

There are several disadvantages to doing this, but the one that irritates me the most is that my runtime exception would contain a nested stacktrace. Basically I would like to re-throw the "IOException" as a RuntimeException (or "IORuntimeException") with the original message and stacktrace, so I can avoid the useless nested stacktrace. The "fact" that I have re-thrown the exception somewhere in the middle seems like just useless noise to me.

Is this possible ? Is there any library that does this ?

Is [this](http://robaustin.wikidot.com/rethrow-exceptions) helpful? — Kazekage Gaara, Jun 08 '12 at 06:53
If you're irritated by nested stacktraces, you're gonna hate most frameworks and libraries, which tend to use them extensively. I'd just get used to it if I were you. — artbristol, Jun 08 '12 at 06:58
@KazekageGaara, good one. I'd upvote that if you post it as an answer. — missingfaktor, Jun 08 '12 at 07:15
@artbristol I know, but I can do my part to minimize the problem and avoid 400 line stacktraces. — krosenvold, Jun 08 '12 at 10:18

score 4 · Answer 1 · answered Jun 08 '12 at 06:49

4

Project Lombok allows you to disable checked exceptions altogether.

answered Jun 08 '12 at 06:49

missingfaktor

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2

Fair enough, but it's too much of a hack to me. I'd rather just do it myself somewhere – krosenvold Jun 08 '12 at 06:52
3

I doubt if there is a non-hacky solution to the problem you are trying to solve. – missingfaktor Jun 08 '12 at 07:14

score 3 · Answer 2 · answered Jun 08 '12 at 07:17

3

Follow up from my comment. Here's an article that has to throw some light on the issue. It uses sun.misc.Unsafe to rethrow exceptions without wrapping them.

answered Jun 08 '12 at 07:17

Kazekage Gaara

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aioobe · Answer 3 · 2012-06-08T07:02:21.803

2

class IORuntimeException extends RuntimeException {

    final IOException ioex;

    public IORuntimeException(IOException ioex) {
        this.ioex = ioex;
    }

    @Override
    public String getMessage() {
        return ioex.getMessage();
    }

    @Override
    public StackTraceElement[] getStackTrace() {
        return ioex.getStackTrace();
    }

    //@Override
    // ...
}

(Full class available here, as produced by Eclipse "Generate Delegate Methods" macro.)

Usage:

try {
    ...
} catch (IOException ioex) {
    throw new IORuntimeException(ioex);
}

edited Jun 08 '12 at 07:02

answered Jun 08 '12 at 06:52

aioobe

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The problem with this approach is that it cannot be generalized for any `Exception` type, and thus causes too much boilerplate and code duplication. – missingfaktor Jun 08 '12 at 07:13
Yes, but the type information is lost. Only if Java had reified generics... then we could have done this with generics. – missingfaktor Jun 08 '12 at 07:20
An interesting aspect of this response is that it does not really work ;) "fillInStackTrace" is called from the the throwable constructor, meaning the member variable in the subclass hasnt been initialized. – krosenvold Jun 13 '12 at 11:29
Ah, so remove @Override ... fillInStackTrace then? – aioobe Jun 13 '12 at 11:34

score 2 · Answer 4 · answered Jun 08 '12 at 12:22

If you're considering the other answer's use of Unsafe (I recommend not, but anyway), another option is to abuse generics to throw a checked exception with this evil pair of methods (from http://james-iry.blogspot.co.uk/2010/08/on-removing-java-checked-exceptions-by.html):

   @SuppressWarnings("unchecked")
   private static <T extends Throwable, A> 
     A pervertException(Throwable x) throws T {
      throw (T) x;
   }


   public static <A> A chuck(Throwable t) {
      return Unchecked.
        <RuntimeException, A>pervertException(t);
   }

You might also check out com.google.common.base.Throwables.getRootCause(Throwable) and just print its (root) stack trace.

score 0 · Answer 5 · answered Feb 19 '13 at 15:38

0

sounds like you actually NEED checked Exceptions

answered Feb 19 '13 at 15:38

Oliver Watkins

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score 0 · Answer 6 · edited May 23 '17 at 11:48

0

As of Java 8 there's another way:

try {
  // some code that can throw both checked and runtime exception
} catch (Exception e) {
  throw rethrow(e);
}

@SuppressWarnings("unchecked")
public static <T extends Throwable> RuntimeException rethrow(Throwable throwable) throws T {
    throw (T) throwable; // rely on vacuous cast
}

* More info here.

edited May 23 '17 at 11:48

Community

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answered Sep 29 '16 at 08:25

AlikElzin-kilaka

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Replace a checked exception with a runtime exception?

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