Eclipse: Delete line shortcut key combo does not work

After delete .metadata directory in a eclipse workspace, my ⌘D key to delete line does not work. Found the solution below:

• Open Preferences -> General -> Keys, then type "Delete line" in the filter text field, it should list all the matching bindings
• Select the command "Delete line" when "Editing text", click Copy Command button to duplicate one, then set the key to "⌘⇧D", then click Apply and Close button.
  
• Restart Eclipse. Now both ⌘⇧D and ⌘D should work. And you can delete the one we just added.
• Open Preferences -> General -> Keys, select the command we just added, and click Restore Command to remove it.