# Example JDI Applications

This example download contains the source code and documentation for three applications written using the JavaTM Debug Interface (JDI) of the Java Platform Debugger Architecture (JPDA). They are provided as educational tools and as starting points for debugger development.

In increasing order of complexity:

- Trace displays traces of program execution. It is very simple (less than 600 lines) yet uses most of the basic JDI functionality. It is a good starting point.
- Jdb is the command line debugger distributed with the J2SE SDK.
- Javadt is the beginnings of a GUI debugger.

Trace is in the `trace` directory. Jdb and Javadt share a package, and are under the `debug` directory.

## Required Set-up

#### Where is JPDA?

New versions of the J2SE SDK have JPDA included. For older versions JPDA must be separately downloaded.

SDKs with JPDA included
  J2SE SDK v1.3 and later and J2SE SDK for Linux v1.2.2
SDKs requiring JPDA download
  J2SE SDK v1.2.1 and v1.2.2 for Solaris and Windows
Other SDKs
  Check with vendor

#### Set-up for J2SE SDKs with JPDA included

Your classpath must include the JDI Library code, which is in `tools.jar` in the `lib` directory. This is needed for both compiling the example code and executing it.

#### Set-up for J2SE SDKs without JPDA - Solaris

Download JPDA v1.0 from http://java.sun.com/products/jpda. Follow the Installation Instructions found there. Pay particular attention to setting the library path.

Your classpath must include the JDI Library code, which is in jpda_home/`lib/tools.jar`. This is needed for both compiling the example code and executing it.

#### Set-up for J2SE SDKs without JPDA - Windows

Download JPDA v1.0 from http://java.sun.com/products/jpda. Follow the Installation Instructions found there. Be sure to add:

            jpda_home\bin

to your path.

Your classpath must include the JDI Library code, which is in jpda_home\`lib\tools.jar`. This is needed for both compiling the example code and executing it.