Debugging Java programs using System i Debugger

The easiest way to debug Java™ programs that run on your system is to use the System i® Debugger. The System i Debugger provides a graphical user interface that enables you to more easily use the debugging capabilities of your system.

For more information about using the System i Debugger to debug and test Java programs that run on your server, see IBM® System i Debugger.

System debugging for IBM Technology for Java
These instructions present several options for debugging IBM Technology for Java JVMs.
Debug operations
You can use the interactive display of your server to use the *DEBUG option to view the source code before running the program. Then, you can set breakpoints, or step over or into a program to analyze errors while the program is running.
Using the QIBM_CHILD_JOB_SNDINQMSG environment variable for debug
The QIBM_CHILD_JOB_SNDINQMSG environment variable is the variable that controls whether the batch immediate (BCI) job, where the Java virtual machine runs, waits before starting the Java virtual machine.
Debugging Java classes loaded through a custom class loader
To use the interactive display of your server to debug a class loaded through a custom class loader, complete the following steps.
Debugging servlets
Debugging servlets is a special case of debugging classes loaded through a custom class loader. Servlets run in the Java runtime of an application server such as IBM WebSphere® Application Server for IBM i or the IBM Integrated Web Application Server for i. You have several options to debug servlets.

Parent topic: Debugging Java programs on IBM i

Related concepts:

Java Platform Debugger Architecture

Finding memory leaks

Using the Generate JVM Dump command