Print the stack trace of an exception

Question

How do I print the stack trace of an exception to a stream other than stderr? One way I found is to use getStackTrace() and print the entire list to the stream.

If you want to get exception trace as String you can call `getStackTrace` method of Trowable (the Exception) that will return array of `StackTraceElement` objects that you can combine to one String (using toString method of that object to get one line of a trace). — jcubic, Dec 04 '13 at 07:34

Mike Deck · Answer 1 · 2013-06-21T20:17:43.830

91

There is an alternate form of Throwable.printStackTrace() that takes a print stream as an argument. http://download.oracle.com/javase/6/docs/api/java/lang/Throwable.html#printStackTrace(java.io.PrintStream)

E.g.

catch(Exception e) {
    e.printStackTrace(System.out);
}

This will print the stack trace to std out instead of std error.

edited Jun 21 '13 at 20:17

answered Jul 25 '11 at 22:14

Mike Deck

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@FranklinYu, the whole point of the question is that he doesn't want to print to stderr, but to another arbitrary stream. – Mike Deck Feb 16 '16 at 16:34
instead of `System.out` you can use `e.printStackTrace(new PrintStream("path.txt"))` – Mauricio Gracia Gutierrez Jun 30 '22 at 05:48

score 88 · Answer 2 · answered Jul 25 '11 at 22:14

88

Not beautiful, but a solution nonetheless:

StringWriter writer = new StringWriter();
PrintWriter printWriter = new PrintWriter( writer );
exception.printStackTrace( printWriter );
printWriter.flush();

String stackTrace = writer.toString();

answered Jul 25 '11 at 22:14

Maurício Linhares

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This is what i needed (even though I feel really dirty using it!) – Henley Sep 16 '13 at 19:45

score 68 · Accepted Answer · edited Jan 04 '19 at 11:52

68

Throwable.printStackTrace(..) can take a PrintWriter or PrintStream argument:

} catch (Exception ex) {
    ex.printStackTrace(new java.io.PrintStream(yourOutputStream));
}

That said, consider using a logger interface like SLF4J with an logging implementation like LOGBack or log4j.

edited Jan 04 '19 at 11:52

Luc

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answered Jul 25 '11 at 22:13

Bozho

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how would we print this with log4j? log.error(ex.printStackTrace())? – Geoff Langenderfer Jun 17 '22 at 00:06

PatrickMA · Answer 4 · 2017-03-17T15:54:12.577

13

For the android dev minimalists: Log.getStackTraceString(exception)

edited Mar 17 '17 at 15:54

answered Dec 06 '15 at 16:28

PatrickMA

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You can't use this to print to an arbitrary stream. It is useful only if you have a logger configured. – r.v Dec 06 '15 at 21:38
I liked this minimalist approach but it didn't jell with my slf4j :( – killjoy Mar 17 '17 at 15:53

score 11 · Answer 5 · answered Mar 20 '18 at 15:43

11

Apache commons provides utility to convert the stack trace from throwable to string.

Usage:

ExceptionUtils.getStackTrace(e)

For complete documentation refer to https://commons.apache.org/proper/commons-lang/javadocs/api-release/index.html

answered Mar 20 '18 at 15:43

Rathan

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While this answer looks very much correct, it is not an answer to the question. OP asked how he could print the stack trace to another stream. – Buurman Mar 20 '18 at 16:10
Even though this might not answer OP's question, I think this is the best way to have an exception as a String, using a very well established format. Thanks! – Clint Eastwood Feb 20 '19 at 13:57

score 10 · Answer 6 · edited Mar 27 '19 at 14:25

I have created a method that helps with getting the stackTrace:

private static String getStackTrace(Exception ex) {
    StringBuffer sb = new StringBuffer(500);
    StackTraceElement[] st = ex.getStackTrace();
    sb.append(ex.getClass().getName() + ": " + ex.getMessage() + "\n");
    for (int i = 0; i < st.length; i++) {
      sb.append("\t at " + st[i].toString() + "\n");
    }
    return sb.toString();
}

score 3 · Answer 7 · answered Jul 25 '11 at 22:14

3

The Throwable class provides two methods named printStackTrace, one that accepts a PrintWriter and one that takes in a PrintStream, that outputs the stack trace to the given stream. Consider using one of these.

answered Jul 25 '11 at 22:14

templatetypedef

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score 2 · Answer 8 · answered Jan 13 '23 at 07:51

2

With slf4j e.g via lombok's @Slf4j annotation

log.error("error", e);

answered Jan 13 '23 at 07:51

xilef

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score 1 · Answer 9 · edited Jul 25 '11 at 22:28

1

See javadoc

out = some stream ...
try
{
}
catch ( Exception cause )
{
      cause . printStrackTrace ( new PrintStream ( out ) ) ;
}

edited Jul 25 '11 at 22:28

dlev

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answered Jul 25 '11 at 22:14

emory

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score 0 · Answer 10 · answered Jun 08 '20 at 14:41

If you are interested in a more compact stack trace with more information (package detail) that looks like:

  java.net.SocketTimeoutException:Receive timed out
    at j.n.PlainDatagramSocketImpl.receive0(Native Method)[na:1.8.0_151]
    at j.n.AbstractPlainDatagramSocketImpl.receive(AbstractPlainDatagramSocketImpl.java:143)[^]
    at j.n.DatagramSocket.receive(DatagramSocket.java:812)[^]
    at o.s.n.SntpClient.requestTime(SntpClient.java:213)[classes/]
    at o.s.n.SntpClient$1.call(^:145)[^]
    at ^.call(^:134)[^]
    at o.s.f.SyncRetryExecutor.call(SyncRetryExecutor.java:124)[^]
    at o.s.f.RetryPolicy.call(RetryPolicy.java:105)[^]
    at o.s.f.SyncRetryExecutor.call(SyncRetryExecutor.java:59)[^]
    at o.s.n.SntpClient.requestTimeHA(SntpClient.java:134)[^]
    at ^.requestTimeHA(^:122)[^]
    at o.s.n.SntpClientTest.test2h(SntpClientTest.java:89)[test-classes/]
    at s.r.NativeMethodAccessorImpl.invoke0(Native Method)[na:1.8.0_151]

you can try to use Throwables.writeTo from the spf4j lib.

Print the stack trace of an exception

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