The Debug Panel appears when Debug Mode is on, with several informational tabs and buttons. DrJava displays currently watched fields and variables with their values in a table in the Watches tab. The Stack tab displays the current stack trace any time a method has been suspended, and the Threads tab shows all current threads along with their status at that point in time. Most of these tabs provide context (right-click) menus for easy access to related commands, such as scrolling to a line in a stack frame, or resuming a suspended thread.
Watching Fields and Variables. You can watch the values of class fields and local variables by entering the field or variable name into a row in the Watches table. Any time a method is suspended (e.g. after a breakpoint or step), the current value of the field or variable (if any) is displayed. Watches can be removed from the table by deleting the name and pressing Enter. You cannot enter expressions that need to be evaluated into the watch table. For example, "s.length" is not a valid watch entry. Type expressions like these into the Interactions Pane to see their values.