I am using Collections and Comparator class for sorting of values. This is working fine in the local development environment.
When I deploy it to the Unix Test environment, it is throwing a java.lang.NoClassDefFoundError exception.
Any pointers is deeply appreciated.
In your local enviroment you're using some libraries, that are not provided in your test enviroment. ClassNotFoundException usualy states witch classes it cannot find. If the missing classes are present in your test enviroment, check your classpath.