The simplest way to launch a Java program is to run it using a Java Application launch configuration. This launch configuration type uses information derived from the workbench preferences and your program's Java project to launch the program.
You can also launch a Java program by selecting a project instead of the compilation unit or class file. You will be prompted to select a class from those classes that define a main method. (If only one class with a main method is found in the project, that class is launched as if you selected it.)
Connecting to a remote VM with the Java Remote Application launcher
Re-launching a program
Running and debugging
Setting execution arguments
Stepping through the execution of a program