How to get a System's total CPU usage percentage using a java program

[userj2ee]

Hi,

I need to find the system's total CPU usage percentage ( as we see in Windows Task Manager) using a java program. I am able to find the CPU usage time for one process using the OperatingSystemMXBean API. But i am not able to find a way to find the CPU usage percentage for all the process running on a system.
I cannut use any third party tools to acheive this. Are there any third party jars available which can help me in getting this data?

Thanks
Prachi

[toadaly]

There are tons of 3rd party system performance monitors available, such as PerfAnal, but if I were tasked with this problem, I'd write a dirt simple native app that just spits total cpu usage out to stdout, and then I'd exec it in java and read the results.