The editor has its own mechanism for registering keybindings, which is separate from global keybindings (in essence, they belong to the Swing EditorKit for the editor, but there are some registration mechanisms in the editor for this).

If there is a global shortcut bound to a key combination, and also an editor-specific one defined for the type of file being edited, the editor wins if the editor has focus.

The principle difference between editor keybindings and global ones is that the editor supports multi-key bindings (so you could do things like Emacs' Ctrl-X-Ctrl-C as a single binding).

Source: NetBeans FAQ