DEU CERTO! FOI SEGUINDO ESSAS INSTRUÇÕES DESSE FORUM QUE EU CONSEGUI!
"I just hit this problem myself, and it's baffling. You get it in a bunch of different places as you try and treat a Java file as, you know, a Java file but Eclipse hasn't figured out that it's actually a class within your project. The reason it doesn't know (or the reason it didn't know in my case) was because the directory hasn't been marked as a source directory for the project. So you need to tell the project configuration that the file is in a directory that holds source files. Here's how:
Open your project's properties.
Under "Java Build Path", click on the "Source" tab.
Click "Add Folder..."
Find the folder where you have the unrecognized java file. (In my case it was test->Java)
Put a check by the folder. (I put it only by "java" and not by "test" given that the test folder holds a lot of other stuff.)
Click ok, click OK again, perhaps refresh, and you should be good to go."