How to store printStackTrace into a string

Question

How can I get the e.printStackTrace() and store it into a String variable? I want to use the string generated by e.printStackTrace() later in my program.

I'm still new to Java so I'm not too familiar with StringWriter that I think will be the solution. Or if you have any other ideas please let me know. Thanks

Not actually the same question: the other question actually specifies that they just want to convert the result of `Throwable.getStackTrace()` to a string. That could contain quite a bit less information than would be shown by `Throwable.printStackTrace`. — SamB, Feb 05 '20 at 01:56

score 495 · Accepted Answer · edited Jun 19 '16 at 07:43

495

Something along the lines of

StringWriter errors = new StringWriter();
ex.printStackTrace(new PrintWriter(errors));
return errors.toString();

Ought to be what you need.

Relevant documentation:

edited Jun 19 '16 at 07:43

shanet

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answered Jan 27 '11 at 03:59

Zach L

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@Zach L - Thanks for your answer. it worked for me to print the stack trace along with personalized(Customized) error message. Thanks again for your help. – Umamaheshwar Thota Mar 07 '13 at 10:47
3

This prints the nested causes of the thrown exception too which is just what I needed. Thanks! – Tim Stewart Sep 27 '13 at 20:00
4

what about closing `PrintWriter` after usage to release resources? Reading the docs I found that is not necessary for StringWriter. – jelies Jan 22 '14 at 09:29

score 78 · Answer 2 · edited Aug 11 '17 at 05:40

78

Guava makes this easy with Throwables.getStackTraceAsString(Throwable):

Exception e = ...
String stackTrace = Throwables.getStackTraceAsString(e);

Internally, this does what @Zach L suggests.

edited Aug 11 '17 at 05:40

lakshayg

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answered Jan 27 '11 at 04:11

ColinD

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thiagoh · Answer 3 · 2017-02-07T23:24:10.270

20

You can use the ExceptionUtils.getStackTrace(Throwable t); from Apache Commons 3 class org.apache.commons.lang3.exception.ExceptionUtils.

http://commons.apache.org/proper/commons-lang/

ExceptionUtils.getStackTrace(Throwable t)

Code example:

try {

  // your code here

} catch(Exception e) {
  String s = ExceptionUtils.getStackTrace(e);
}

edited Feb 07 '17 at 23:24

answered Feb 13 '14 at 20:42

thiagoh

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score 16 · Answer 4 · answered Jan 27 '11 at 03:59

You have to use getStackTrace () method instead of printStackTrace(). Here is a good example:

import java.io.*;

/**
* Simple utilities to return the stack trace of an
* exception as a String.
*/
public final class StackTraceUtil {

  public static String getStackTrace(Throwable aThrowable) {
    final Writer result = new StringWriter();
    final PrintWriter printWriter = new PrintWriter(result);
    aThrowable.printStackTrace(printWriter);
    return result.toString();
  }

  /**
  * Defines a custom format for the stack trace as String.
  */
  public static String getCustomStackTrace(Throwable aThrowable) {
    //add the class name and any message passed to constructor
    final StringBuilder result = new StringBuilder( "BOO-BOO: " );
    result.append(aThrowable.toString());
    final String NEW_LINE = System.getProperty("line.separator");
    result.append(NEW_LINE);

    //add each element of the stack trace
    for (StackTraceElement element : aThrowable.getStackTrace() ){
      result.append( element );
      result.append( NEW_LINE );
    }
    return result.toString();
  }

  /** Demonstrate output.  */
  public static void main (String... aArguments){
    final Throwable throwable = new IllegalArgumentException("Blah");
    System.out.println( getStackTrace(throwable) );
    System.out.println( getCustomStackTrace(throwable) );
  }
}

[Zach's solution](https://stackoverflow.com/a/4812589/822870) is 3 lines of code. — David Balažic, Feb 07 '19 at 03:02

score 14 · Answer 5 · edited May 23 '17 at 10:31

14

Along the lines of Guava, Apache Commons Lang has ExceptionUtils.getFullStackTrace in org.apache.commons.lang.exception. From a prior answer on StackOverflow.

edited May 23 '17 at 10:31

Community

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answered Jan 06 '13 at 16:59

Mihai Danila

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score 7 · Answer 6 · answered Jan 27 '11 at 03:59

7

StackTraceElement[] stack = new Exception().getStackTrace();
String theTrace = "";
for(StackTraceElement line : stack)
{
   theTrace += line.toString();
}

answered Jan 27 '11 at 03:59

Jonathon Faust

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score 2 · Answer 7 · edited Aug 17 '17 at 16:32

2

Use the apache commons-lang3 lib

import org.apache.commons.lang3.exception.ExceptionUtils;

//...

String[] ss = ExceptionUtils.getRootCauseStackTrace(e);
logger.error(StringUtils.join(ss, System.lineSeparator()));

edited Aug 17 '17 at 16:32

lakshayg

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answered Nov 19 '14 at 18:19

Eric

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`logger.error(StringUtils.join(ss, System.lineSeparator()));` – Pikachu Oct 12 '16 at 23:36

score 1 · Answer 8 · edited May 09 '13 at 16:18

1

call:  getStackTraceAsString(sqlEx)

public String getStackTraceAsString(Exception exc)  
{  
String stackTrace = "*** Error in getStackTraceAsString()";

ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintStream ps = new PrintStream( baos );
exc.printStackTrace(ps);
try {
    stackTrace = baos.toString( "UTF8" ); // charsetName e.g. ISO-8859-1
    } 
catch( UnsupportedEncodingException ex )
    {
    Logger.getLogger(sss.class.getName()).log(Level.SEVERE, null, ex);
    }
ps.close();
try {
    baos.close();
    } 
catch( IOException ex )
    {
    Logger.getLogger(sss.class.getName()).log(Level.SEVERE, null, ex);
    }
return stackTrace;
}

edited May 09 '13 at 16:18

David Starkey

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answered May 09 '13 at 15:58

Stan Towianski

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Using a PrintWriter with a StringWriter seems to be more straightforward. – gouessej Apr 15 '15 at 08:09
Closing the `PrintWriter` closes the `ByteArrayOutputStream`. – user207421 Aug 11 '17 at 05:47

How to store printStackTrace into a string

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