Eclipse: "The import java.io cannot be resolved"

Question

I have several Android projects in Eclipse, and all is fine, except one (a library) that can not resolve any imports.

The java.io imports do resolve fine in other Android projects in the same workspace, and previously (I haven't used it for over a year) this library worked fine, too.

Any ideas?

Answer 1

Check two things

Eclipse preferences

1. Check your Eclipse preferences: Java -> Installed JREs
2. The one that you're using should be marked and it should be a JDK not just a JRE.

Project build path

1. Also check your project's build path: Right click on the project -> Properties -> Java Build Path
2. Check in the libraries folder whether the JRE System Library is present and ...
3. If not add it using Add library -> JRE System Library and then select the correct one (from an installed JDK).

Answer 2

I am using Maven an this is what I did to re-solve -->

1. Right click on project
2. Maven -> Update Project. Make sure you choose 'Force update of Snapshots/Releases'.
3. Also check the 'clean project', 'update project conf from pom' and 'refresh workspace resource options' and click ok.