I don\'t get the exact method to do this. I want a method not for a single project for all projects in eclipse. Please tell me how to solve this problem.
This happened to me after I moved my Android files from one PC to a new PC: I simply copied the folder from P:\Android\ to C:\Android\
To fix the error (using Eclipse), right-click the library (in my case android.jar) in your project. Click "Properties", click "Javadoc Location", and fix the Javadoc location path.
For example, I changed it from "file:/P:/Android/android-sdk-windows/docs/reference" to "file:/C:/Android/android-sdk-windows/docs/reference"
Then click "Validate". Then click "Apply". Then click "OK"
now hovering over a method or constant gives me the API info again :-)