How to restore default perspective settings in Eclipse IDE
From the Window menu, Reset Perspective
1) Go to "Window".
2) Then click on "Open Perspective",
3) Then click on "Other",
4) Select "Java(Default)" and click "OK"
Then again go to "Window" and click on "Reset Perspective"
There is no keyboard shortcut for restoring the perspective directly AFAIK. To open the Window menu (where Reset Perspective resides), try Alt-W. If that does not work, I guess your Eclipse has hung for some reason. Another shortcut you might want to try is F10 (should open the main menu).