Error in Eclipse (for Android): The type java.lang.String cannot be resolved. It is indirectly referenced from required .class files

Question

I am trying to run an Android project that someone else has created. I have opened the project in Eclipse as:

File --> New --> Project --> Android Project from existing code

Here are the first two lines of one of Java files:

package aa.bb.cc;

import java.io.File;

There is red cross sign at the beginning of these lines and when I hold the mouse over them I get this message for the first line: The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files anfd for the second line get this message: The import java.net cannot be resolved.

What is the reason and how can I resolve these error messages?

Thanks.

Answer 1

Do one more step before running:

Right Click(Project) -> Properties -> Java Build Path -> Libraries -> 
                                          Add Library -> Select the Java Library

Click OK and then clean-build (Project -> Clean & Project -> Build All or Ctrl+B) your project. It should be fine.

Answer 2

This is an annoying Eclipse Bug which seems to bite now and then. See http://dev-answers.blogspot.de/2009/06/eclipse-build-errors-javalangobject.html for a possible solution, otherwise try the following;

Close the project and reopen it.

Clean the project (It will rebuild the buildpath hence reconfiguring with the JDK libraries)

OR

Delete and Re-import the project and if necessary do the above steps again.