Quartz is a full-featured, open source job scheduling system that can be integrated with, or used along side virtually any J2EE or J2SE application - from the smallest stand-alone application to the largest e-commerce system. Quartz can be used to create simple or complex schedules for executing tens, hundreds, or even tens-of-thousands of jobs jobs whose tasks are defined as standard Java components or EJBs. The Quartz Scheduler includes many enterprise-class features, such as JTA transactions and clustering.
What I am trying to introduce here is a full fledged Java Instant messenger, which has all the features supplied by commercial messengers like Yahoo or MSN. Although it cannot compared to be in par with those messengers, it is an attempt by me to learn Advanced Java and JNI concepts. The challenges I faced here were often overcome by referring to numerous sites, which nearly zeroes in or completely solved the issues I faced at that point of time. It improved my learning curve and also believe would do the same to you too. Ofcourse, there are some bugs and glitches, which I hope you would excuse. Thanks to anyone who takes the pain to report them or even suggest better way of doing things to me.