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 An

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).