Eclipse Search not working ( java search class filename must end with .class)

Follow the below steps to take care of this. Most probably the index files used by Eclipse would have got corrupted and if we reindex them, it helps.

1. Close Eclipse
2. Delete /.metadata/.plugins/org.eclipse.jdt.core/*.index
3. Delete /.metadata/.plugins/org.eclipse.jdt.core/savedIndexNames.txt
4. Start Eclipse again