One option is to filter derived resources. In the upper right corner of the ‘Open Resource’ dialog there is an arrow you can click to bring up a dropdown menu for filtering. Uncheck the ‘Show Derived Resources’ option, if it is checked.
If you still see ‘.class’ files, they probably aren’t being marked as derived. If they’re by themselves in their own folder hierarchy you can fix this by right-clicking the root folder to edit folder properties, and check the ‘Derived’ checkbox. If they’re mixed with your ‘.java’ files…tough luck, you’ll need to set the derived property on each ‘.class’ file by hand.
As far as I can tell there’s no way to mark class files as derived resources globally for the workspace, but I believe when you create a new Java project the ‘bin’ folder is marked as derived by default (if you use the default wizard settings)
Here are some screenshots from Eclipse Kepler. The first shows how to filter derived resources by unchecking ‘Show Derived Resources’ in the Open Resource dialog. The second shows how to set the ‘Derived’ property on a resource.
