Java Exception toString() inclusive causes

Question

Is there any good function collecting all causes of an Exception in a string? The method printStackTrace() collect them with their StackTraces:

   HighLevelException: MidLevelException: LowLevelException
           at Junk.a(Junk.java:13)
           at Junk.main(Junk.java:4)
   Caused by: MidLevelException: LowLevelException
           at Junk.c(Junk.java:23)
           at Junk.b(Junk.java:17)
           at Junk.a(Junk.java:11)
           ... 1 more
   Caused by: LowLevelException
           at Junk.e(Junk.java:30)
           at Junk.d(Junk.java:27)
           at Junk.c(Junk.java:21)
           ... 3 more

But I just want the getMessage() of the causes:

   HighLevelException: MidLevelException: LowLevelException
   Caused by: MidLevelException: LowLevelException
   Caused by: LowLevelException

Should I write my own function?

Yes you should. If you want that in a log file though, depending on the log framework you may be able to use the correct template to log the exception as you want. — Michael Laffargue, Jul 31 '13 at 06:52

Tala · Accepted Answer · 2013-07-31T07:10:57.777

6

Yes, you'll have to write a simple method for that

static String message(Throwable e) {
    StringBuilder sb = new StringBuilder();
    sb.append(e.getMessage());
    Throwable t = e.getCause();
    while (t != null) {
        sb.append("\nCaused by: ").append(t.getMessage());
        t = t.getCause();
    }
    return sb.toString();
}

edited Jul 31 '13 at 07:10

answered Jul 31 '13 at 06:52

Tala

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I've added `sb.append(e.getMessage());` before the loop. I guess you're talking about it? – Tala Jul 31 '13 at 07:09
You're getting the first level, then the next level printed is e.getCause().getCause(). – Joachim Isaksson Jul 31 '13 at 07:10
1

Thanks! there was a typo `getCause` instead of `getMessage` – Tala Jul 31 '13 at 07:11
Yes, it was my idea, even if I prefer `getLocalizedMessage()` to `getMessage()` – Olivier Faucheux Jul 31 '13 at 07:50
If this answered your question, would mind accepting it? Thanks – Tala Jul 31 '13 at 08:30
@Tala Better would be `t != null && t.getCause() != t` i have seen many exception which reference themself – André Mar 29 '23 at 08:01

score 1 · Answer 2 · answered Jul 31 '13 at 08:05

You can create a custom exception and override the getMessage() function.

here is a sample where I am collecting Stacktraces:

@Override
public String getMessage()
{
    for (StackTraceElement element : this.getStackTrace() ){
              result.append( element );
              result.append( NEW_LINE );
            }
            return result.toString();
}

You can use your own version of code to fit your requirement.

Java Exception toString() inclusive causes

2 Answers2