To suspend an executing thread:
The thread suspends its execution. The current call stack for the thread is displayed, and the current line of execution is highlighted in the editor in the Debug Perspective.
When a thread suspends, the top stack frame of the thread is automatically selected. The Variables View shows the stack frame's variables and their values. Complex variables can be further examined by expanding them to show the values of their members.
When a thread is suspended and the cursor is hovered over a variable in the Java editor, the value of that variable is displayed.
Catching Java exceptions
Resuming the execution of suspended threads
Stepping through the execution of a program