it seems that port will be still opened even so if I undeploy the war file
important points to mention :
1) this problem does not arise under windows
2)this problem appears under linux : after undeploy of the war file i used to check whether the port still in use or not using 2 following commands
a) it will be still listening if i use the command
#netstat -anp | grep 11900
tcp 0 0 0.0.0.0:11900 0.0.0.0:* LISTEN -
b) the port appears to be unused if i use the command
In order to find out why your server did not shutdown, you would probably have to do a remote debug and find out whether the shutdown call reached the server.
If you feel the threads did not get interrupted, take a jstack of the process and see where the threads are stuck.
I would recommend using a library such as netty if you are trying to write an NIO server, instead of re-inventing the wheel.