jstack查看死锁情况

一、首先写一段死锁程序：

public class DeadlockTest {
    public static String obj1 = "obj1";
    public static String obj2 = "obj2";
    public static void main(String[] args){
        Thread a = new Thread(() -> {
            try{
                System.out.println("Lock1 running");
                while(true){
                    synchronized(DeadlockTest.obj1){
                        System.out.println("Lock1 lock obj1");
                        Thread.sleep(3000);//获取obj1后先等一会儿，让Lock2有足够的时间锁住obj2
                        synchronized(DeadlockTest.obj2){
                            System.out.println("Lock1 lock obj2");
                        }
                    }
                }
            }catch(Exception e){
                e.printStackTrace();
            }
        });
        Thread b = new Thread(() -> {
            try{
                System.out.println("Lock2 running");
                while(true){
                    synchronized(DeadlockTest.obj2){
                        System.out.println("Lock2 lock obj2");
                        Thread.sleep(3000);
                        synchronized(DeadlockTest.obj1){
                            System.out.println("Lock2 lock obj1");
                        }
                    }
                }
            }catch(Exception e){
                e.printStackTrace();
            }
        });
        a.start();
        b.start();
    }
}

二、命令格式：jstack -l PID >> test.txt

这里可以将信息输出到文本中，方便查看

三、打开任务管理器找到该程序的PID，在jdk的bin目录下执行命令