Intellij: Adding 'Interface' to my context menu in the Project Pane

New | Java Class, Create New Class dialog appears, in this dialog you can choose Kind between one of the following:

• Class
• Interface
• Enum
• Annotation

(tested with IDEA 9.0.3)

If you want Interface directly in the New list, then you have to add new template in Settings | File Templates, name it something like Java Interface and copy the contents of the Interface template into this one.

Also you can create a shortcut to save some secs.

Alt+Ctr+S -> Keymap -> in search box type 'create new' and select Java class and then assign any shortcut like Ctrl+N.