could not import android classes

I have imported an existing android project into eclipse, the src code shows some errors saying

"The type java.lang.Class cann开发者_StackOverflowot be resolved. It is indirectly referenced from required .class files" and "the import android cannot be resolved"

Have you downloaded the Android sdk & used it to download the specific target-sdk that your project is built for? If you haven't then you should do this first.

After that you need to tell eclipse where your android-sdk is present. This document explains everything.

http://developer.android.com/sdk/installing.html