Tuesday, February 14, 2012

How can I hide long class paths in stack traces to make them readable?


Often stack traces can get so verbose from long class paths that they are very painful to read. Here's an example:




1) No implementation for java.util.Set<
com.mydomain.myapp.android.activities.catbrowser.generalizedbrowser.listview.
helpers.databaseitem.itemmanipulators.ItemManipulator<
com.mydomain.myapp.flash.Cat>> annotated with
@com.google.inject.assistedinject.Assisted(value=) was bound.
while locating
java.util.Set<
com.mydomain.myapp.android.activities.catbrowser.generalizedbrowser.listview.
helpers.databaseitem.itemmanipulators.ItemManipulator<
com.mydomain.myapp.flash.Cat>> annotated with
@com.google.inject.assistedinject.Assisted(value=)



...



If I could trim the class path, only showing class names and methods, it would look like this:




1) No implementation for
Set<ItemManipulator<Cat>> annotated with @Assisted(value=) was bound.
while locating Set<ItemManipulator<Cat>> annotated with @Assisted(value=)



...



I first asked this as a Guice-specific question , but realized it applies to stack traces in general. Is there any way to configure Java or Eclipse to do this natively? If not, is there a plugin or even external tool to accomplish this?

3 comments:

  1. You can set the default UncaughtExceptionHandler and modify the stack trace before printing to System.err. You may have to play around with the regex, but this will work:

    Thread.setDefaultUncaughtExceptionHandler(new UncaughtExceptionHandler() {
    @Override
    public void uncaughtException(Thread t, Throwable e) {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    PrintStream ps = new PrintStream(baos);
    e.printStackTrace(ps);
    String withoutClasspaths = baos.toString().replaceAll("(\\w+\\.){2,}(\\w*)", "$2");
    System.err.println(withoutClasspaths);
    }
    });

    ReplyDelete
  2. To produce more readable traces, paste the stack trace into Notepad++ and the following regular expression. The same expression could also be used in a scripting language.

    I paste the trace into Notepad++ and use the following search and replace settings.

    Search pattern: \w[a-z\d_\.]+\.([A-Z][A-Za-z\d_]*)

    Replace with: \1

    Search Settings: match case enabled, Regular expression search mode.

    ReplyDelete
  3. If you use logback, then you can use layout to output logs in any way you like
    http://logback.qos.ch/manual/layouts.html.

    Outputting a class like java.lang.String as j.l.String is quite common in stack traces

    ReplyDelete