title: Does Eclipse have any cache or the like or settings that can get corrupted
body: <p>Does Eclipse have any persistent settings (that can get corrupted). </p>
  
  <p>All of sudden my eclipse is doing strange things -- java programs won't run (though I can run them fine from the command line).</p>
  
  <p>If there is such a things -- how do I purge it?</p>