Debugging a Java applet
When debugging an applet, you must begin by debugging the sun.applet.AppletViewer
class. After you have begun debugging this class, you can open the source for any class
which is part of your applet and set breakpoints.
You can start to debug an applet by following these steps:
- Issue the following command on your local system:
idebug -qlang=java
sun.applet.AppletViewer <applet_location>
Where <applet_location> is one of the following:
- a URL pointing to the applet you want to debug. The URL must begin with http://
or file:/ (only one slash for URLs beginning with file.)
- the file name of the applet you want to debug only. The file must exist in the directory
where you issued the idebug command.
- Click OK.
- If you are using JDK 1.1.x or JDK 1.2.2 prior to service release 9:
- From the main menubar, select Source > Open New Source.
- Enter the name of the applet class you are debugging.
- If you are using JDK 1.2.2 service release 9+ or JDK 1.3:
- From the breakpoint menu, select Set method breakpoint
- Set a deferred method breakpoint on the applet class for either the
start() or init() methods and run
- Set your breakpoint and run.
We recommend that you set a breakpoint on the init() or start()
methods since these are the first methods that are called by the applet viewer.
Once you have set this breakpoint you can debug your applet as you would debug a Java
application.

idebug command