The Eclipse debugger can examine Java code locally or remotely. In Chapter 13, "The Eclipse Plug-in Architecture," you will find information about debugging plug-ins. Here are the salient points about out-of-the-box Eclipse debugging:
The Debug perspective presents the basic grouping of views to help you debug your code. You can use a number of additional views by selecting Window, Show View, Other and looking in the Debug category.
The debugging of standalone Java code is quite straightforward and complements JUnit testing. Standard features such as Step Into, Step Over, and Resume are all supported. Use Step Filter tells the debugger what code it can safely skip when it is stepping into code during a debug session.
Remote debugging is activated by running the process to be debugged using command-line options that make the JVM listen on a socket for external commands. Once the Eclipse debugger is connected to the external process, it becomes just another debug target with most of the available features of the debugger.