if you want to include android library resource in your project .

like you want the resource of Context class which is imported from import android.content.Context , than just select Context or just hover it , than there you will find a text , like No Source found , and there is also one special thing , Attach new Resource , just click in it , now just go to that place where your android installation is performed and select Resource folder , press Ok and now you can easily access the resource file .