Java多线程____线程死锁例子

1：两个任务以相反的顺序申请两个锁，死锁就可能出现

2：线程T1获得锁L1，线程T2获得锁L2，然后T1申请获得锁L2，同时T2申请获得锁L1，此时两个线程将要永久阻塞，死锁出现



package com.zs.test;

public class DeadLock {
public static String objA = "objA";
public static String objB = "objB";

public static void main(String[] args) {
Thread a = new Thread(new RunnableA());
Thread b = new Thread(new RunnableB());
a.start();
b.start();
}
}

class RunnableA implements Runnable {
@Override
public void run() {
while (true) {
System.out.println("线程A__:锁定objA___休眠3秒___锁定objB");
synchronized (DeadLock.objA) {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
synchronized (DeadLock.objB) {
System.out.println("___"+DeadLock.objA);
}
}
}
}
}

class RunnableB implements Runnable {
@Override
public void run() {
try {
while (true) {
System.out.println("线程B__:锁定objB___休眠3秒___锁定objA");
synchronized (DeadLock.objB) {
Thread.sleep(3000);
synchronized (DeadLock.objA) {
System.out.println("___"+DeadLock.objB);
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}