Why can't eclipse resolve class in same package?

Alternatively, you can highlight the project :

Choose Clean ... from Project menu and if you have activated the Build Automatically option (in the same menu), the classes will be generated anew.

I could resolve it: On another project (from the same git repo), I had the same issue on several files in different packages. All I had to do was writing a white-space into the file, remove it again and save, so eclipse would re-compile it (I guess).

Some kind of a strange behaviour... :S

I got the same error in Maven project. Running Maven Clean and closing the project and reopening didn't work for me. Right click project -> Maven -> Update Project worked for me.