For easier code reading the following refactoring can be done:
- Modifier 'private' is redundant for enum constructors (remove)
- Modifier 'public' is redundant for interface fields (remove)
- Modifier 'static' is redundant for interface fields (remove)
- Modifier 'final' is redundant for interface fields (remove)
- Unnecessary semicolon (remove)
- Merge sequential if's
- Remove exception in throws if more general exception listed
- Remove unused imports
- Redundant boxing/unboxing
-Unnecessary zero length array usage (replace with EMPTY_ARRAY, etc)