Avoiding “resource is out of sync with the filesystem”

Question

I develop Java code with Eclipse and regularly get this message:

resource is out of sync with the filesystem.

Right-click > Refr

Answer 1

For the new Indigo version, the Preferences change to "Refresh on access", and with a detail explanation : Automatically refresh external workspace changes on access via the workspace.

As “resource is out of sync with the filesystem” this problem happens when I use external workspace, so after I select this option, problem solved.