Appendix B. DrJava Errors

Even though we try hard, it is an unfortunate reality that DrJava contains errors. This appendix describes how DrJava will most likely react in case of an error, and how you can help improve DrJava if you encounter an error.

How DrJava Reacts. When an internal DrJava error occurs, DrJava puts information about the error in a list and displays a "DrJava Errors" toolbar button that is normally hidden. You can view this list by clicking on that button or by selecting the "DrJava Errors" command in the Help menu.

In the "DrJava Errors" dialog, you can use the "Previous" and "Next" buttons to browse the list of errors, or press the "Copy This Error" button to copy the information about the currently displayed error to the clipboard. This information is useful to us in finding the cause of the error. The "Dismiss" button clears the list of errors, hides the "DrJava Errors" button, and closes the window. The "Close" button leaves the list as it is and only closes the window.

Optionally, DrJava may also display a popup notification window when the first error occurs. You may disable this popup under "Notifications" in the Preferences window (see Configuring DrJava). In most cases, an internal DrJava error will not be fatal, and most likely you will be able to continue working even without restarting DrJava. Therefore, DrJava does not display this popup for every error, but only when the list of errors is empty, and then an error occurs. This is to inform you that DrJava might be unstable now.

The popup window contains a "Close" button to close the window and continue working, and a "More Information" button that will open up the "DrJava Errors" dialog. It also provides a checkbox labeled "Keep showing this notification" that allows you to disable the popup; disabling this checkbox does the same as disabling the "Show a notification window when the first DrJava error occurs" option in the Preferences window (see Configuring DrJava).

Submitting a Bug Report. If you encounter an error, we would be thrilled if you helped us improve DrJava by submitting a bug report on our SourceForge site at

To submit a bug report, please follow these instructions:

  1. Point your favorite browser to the URL above.

  2. Click on the link labeled "Bugs" (it's in the long row of links: "Summary | Admin | Home Page | Tracker | Bugs | ...").

  3. Optional: If you have the time, please browse through the list of bugs to see if the error you encountered has already been reported.

  4. Click on the link labeled "Submit New" (it's on the left, below the long row of links).

  5. Optional: If you have a SourceForge account, please log in before submitting the bug report. This is not necessary, but it enables us to communicate with you if we need more information.

  6. Please enter a short description in the "Summary" field, and a more detailed description that includes the information from the "DrJava Errors" window in the "Detailed Description" field. Try to be as specific as you can. Here's a list of questions you might want to consider in your description:

    • What operating system are you using?

    • What version of the Java JDK are you using (1.5, 6, etc.)? Do you have multiple versions of the JDK (or maybe the JRE) installed?

    • Did you have a project open, or where you using just a bunch of files not part of a project?

    • What were you doing just before the error occurred? Were you compiling, saving a file, debugging, using find/replace, etc.?

    • What happened after the error occurred? Could you continue with your work, or was it so bad that you had to quit DrJava?

  7. Press the "Submit" button on the bottom of the page

That's it! Thank you for helping us make DrJava better!