Find out where a thread has been blocked

In java, i have 2 threads started at the same time. However, i noticed the thread 2 is being blocked but i do not know where. Is there a way in java to find out where a thread has been开发者_如何学Python blocked/waiting? thank u.

You could use jstack to get the stack traces for all threads. That'll tell you where exactly in the code your thread is blocked.

To get a more detailed picture of what's happening inside your process, you could use VisualVM.

You can use the isAlive() method to verify if the thread is still active or not. Here's a sample code to check all the threads in your memory:

public class ThreadStates{
 public static void main(String[] args){
  Thread t = new Thread();
  Thread.State e = t.getState(); 
  Thread.State[] ts = e.values(); 
  for(int i = 0; i < ts.length; i++){
   System.out.println(ts[i]); 
  }   
 }
}

You can use jstack to find where a thread is blocked. However if you want to check a thread within the same program you can using thread.getStackTrace()