Showing an Element in the Package Explorer View
You can reveal an element's location in the Package Explorer view
Select a Java element or activate a Java editor.
From the menu bar, select Navigate > Show In > Package Explorer.
If the Package Explorer is not already open, then it opens in the
current perspective. The workbench navigates to the selected element (or the edited compilation unit).
From the Java editor's pop-up menu, select
Show In > Package Explorer. The currently edited compilation unit will be revealed.
Note: The element might not be revealed if Package Explorer filters are active or the
Show Members in Package Explorer preference is cleared on the
Java > Appearance
Setting execution arguments
Java preference page