如何打印或获取在服务器上运行的应用程序的JRE版本？

I mean using javacode I want to find the JRE version of application but not server. In my production server I am having thousands of applications in java like tomcat,websphere,axway etc. I want to know particular application jre version.I will write a class and I want print using that. That class will be placed in particular application.I mean using javacode I want to find the JRE ve