Fixed some compiler warnings.

Fixed bunch of the compiler warnings being reported through eclipse.
Tighten the method signature.

Change the visibility of the utility method being added through
https://github.com/bvahdat/hawtio/commit/a842281b6925a85656a0a8767466915
e4f15d3a3
Merge pull request #824 from bvahdat/master

Fixed some compiler warnings, thanks @bvahdat!