How can I get the current stack trace in Java?

How do I get the current stack trace in Java, like how in .NET you can do Environment.StackTrace?

I found Thread.dumpStack() but it is not what I want - I want to get the stack trace back, not print it out.

7

22 Answers

You can use Thread.currentThread().getStackTrace().

That returns an array of StackTraceElements that represent the current stack trace of a program.

10

Thread.currentThread().getStackTrace();

is fine if you don't care what the first element of the stack is.

new Throwable().getStackTrace();

will have a defined position for your current method, if that matters.

9

for (StackTraceElement ste : Thread.currentThread().getStackTrace()) { System.out.println(ste);
}

2

Thread.currentThread().getStackTrace();

is available since JDK1.5.

For an older version, you can redirect exception.printStackTrace() to a StringWriter() :

StringWriter sw = new StringWriter();
new Throwable("").printStackTrace(new PrintWriter(sw));
String stackTrace = sw.toString();

1

Tony, as a comment to the accepted answer, has given what seems to be the best answer which actually answers the OP's question:

Arrays.toString(Thread.currentThread().getStackTrace()).replace( ',', '\n' );

... the OP did NOT ask how to get a String from the stack trace from an Exception. And although I'm a huge fan of Apache Commons, when there is something as simple as the above there is no logical reason to use an outside library.

2

You can use Apache's commons for that:

String fullStackTrace = org.apache.commons.lang3.exception.ExceptionUtils.getStackTrace(e);

3

On android a far easier way is to use this:

import android.util.Log;
String stackTrace = Log.getStackTraceString(exception); 

2

Another solution (only 35 31 characters):

new Exception().printStackTrace();
new Error().printStackTrace();

1

To get the stack trace of all threads you can either use the jstack utility, JConsole or send a kill -quit signal (on a Posix operating system).

However, if you want to do this programmatically you could try using ThreadMXBean:

ThreadMXBean bean = ManagementFactory.getThreadMXBean();
ThreadInfo[] infos = bean.dumpAllThreads(true, true);
for (ThreadInfo info : infos) { StackTraceElement[] elems = info.getStackTrace(); // Print out elements, etc.
}

As mentioned, if you only want the stack trace of the current thread it's a lot easier - Just use Thread.currentThread().getStackTrace();

1

Silly me, it's Thread.currentThread().getStackTrace();

In Java 9 there is a new way:

public static void showTrace() { List<StackFrame> frames = StackWalker.getInstance( Option.RETAIN_CLASS_REFERENCE ) .walk( stream -> stream.collect( Collectors.toList() ) ); for ( StackFrame stackFrame : frames ) System.out.println( stackFrame );
}

1

Getting stacktrace:

StackTraceElement[] ste = Thread.currentThread().getStackTrace();

Printing stacktrace (JAVA 8+):

Arrays.asList(ste).forEach(System.out::println);

Printing stacktrage (JAVA 7):

StringBuilder sb = new StringBuilder();
for (StackTraceElement st : ste) { sb.append(st.toString() + System.lineSeparator());
}
System.out.println(sb);

I suggest that

 Thread.dumpStack()

is an easier way and has the advantage of not actually constructing an exception or throwable when there may not be a problem at all, and is considerably more to the point.

3

To string with guava:

Throwables.getStackTraceAsString(new Throwable())

I have a utility method that returns a string with the stacktrace:

static String getStackTrace(Throwable t) { StringWriter sw = new StringWriter(); PrintWriter pw = new PrintWriter(sw, true); t.printStackTrace(pw); pw.flush(); sw.flush(); return sw.toString();
}

And just logit like...

...
catch (FileNotFoundException e) { logger.config(getStackTrace(e));
}

6

try {
}
catch(Exception e) { StackTraceElement[] traceElements = e.getStackTrace(); //...
}

or

Thread.currentThread().getStackTrace()

2

Maybe you could try this:

catch(Exception e)
{ StringWriter writer = new StringWriter(); PrintWriter pw = new PrintWriter(writer); e.printStackTrace(pw); String errorDetail = writer.toString();
}

The string 'errorDetail' contains the stacktrace.

StackTraceElement[] stackTraceElements = Thread.currentThread().getStackTrace();

The last element of the array represents the bottom of the stack, which is the least recent method invocation in the sequence.

A StackTraceElement has getClassName(), getFileName(), getLineNumber() and getMethodName().

loop through StackTraceElement and get your desired result.

for (StackTraceElement ste : stackTraceElements )
{ //do your stuff here...
}

2

You can use jstack utility if you want to check the current call stack of your process.

Usage: jstack [-l] <pid> (to connect to running process) jstack -F [-m] [-l] <pid> (to connect to a hung process) jstack [-m] [-l] <executable> <core> (to connect to a core file) jstack [-m] [-l] [server_id@]<remote server IP or hostname> (to connect to a remote debug server)
Options: -F to force a thread dump. Use when jstack <pid> does not respond (process is hung) -m to print both java and native frames (mixed mode) -l long listing. Prints additional information about locks -h or -help to print this help message

I used answers from above and added formatting

public final class DebugUtil { private static final String SEPARATOR = "\n"; private DebugUtil() { } public static String formatStackTrace(StackTraceElement[] stackTrace) { StringBuilder buffer = new StringBuilder(); for (StackTraceElement element : stackTrace) { buffer.append(element).append(SEPARATOR); } return buffer.toString(); } public static String formatCurrentStacktrace() { StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace(); return formatStackTrace(stackTrace); }
}

For people, who just want to get the current stacktrace to their logs, I would go with:

getLogger().debug("Message", new Throwable());

Cheers

1

This is an old post, but here is my solution :

Thread.currentThread().dumpStack();

More info and more methods there :

4