Find out which piece of code in an online Java application is consuming a lot of performance

from:http://chenjianjx.iteye.com/blog/1681681

You find that your machine has a CPU usage of 100%, and it is found to be the result of your Java application, but which code in this application eats the performance?

Here's a share from a colleague:

1. Find out the thread that eats the performance first: Top-h-P PID, find the thread ID that consumes the most performance (leftmost column)
2. Get the 16 binary representation of thread ID: printf ' 0x%x\n ' thread ID
3. Then generate a jstack, such as the kill-3 PID
4. Search the generated jstack for the 16 binary representation of the thread ID

Find out which piece of code in an online Java application is consuming a lot of performance