Eclipse doesn't see file even it was in the package
<p>I have worked on a project in Java Spring and using Eclipse, I met this weird thing 2 days ago, everything run ok and it suddenly corrupted.</p>

<p>In Project Explorer the "java" and "resources" folders exist, but in Package Explorer, they don't show. Eclipse knew that "java" and "resources" as package, but it didn't see the file below, and it caused a thousand of errors because of this. Almost of errors were "Some class cannot be resolved".
See the images below:</p>

<p><img src="https://i.stack.imgur.com/7siG5.png" alt="Project Explorer"></p>

<p><img src="https://i.stack.imgur.com/8tX8J.png" alt="Package Explorer"></p>

<p>I have tried many ways: clean, rebuild, re-import, restart eclipse, switch workspace, re-checkout the project in another place, download another eclipse but it is still the same.
Does anyone know how to solve this thing?</p>