/**
当两个线程或者多个线程互相锁定的情况就叫死锁
避免死锁的原则
解决死锁的基本方法：
当两个线程或线程者多个互相锁定时就形成了死锁。【使用Synchronized关键字 加锁的时候，要避免死锁的发生。】
避免死锁的原则：
? 顺序上锁，反向解锁。
注意：
切记尽量不要使用同步代码块的嵌套！
JAVA线程的API中很多过时方法都构成了死锁，因此不能调用。
?*/
public class DeadLock {
????public static void main(String[] args) {
????????Object o1 = new Object();
????????Object o2 = new Object();
// t1和t2两个线程共享o1,o2
????????Thread t1 = new MyThread1(o1,o2);
????????Thread t2 = new MyThread2(o1,o2);
????????t1.start();
????????t2.start();
????}
}
class MyThread1 extends Thread{
????Object o1;
????Object o2;
????public MyThread1(Object o1,Object o2){
????????this.o1 = o1;
????????this.o2 = o2;
????}
????public void run(){
????????synchronized (o1){
????????????try {
????????????????Thread.sleep(1000);
????????????} catch (InterruptedException e) {
????????????????e.printStackTrace();
????????????}
????????????synchronized (o2){
????????????}
????????}
????}
}
class MyThread2 extends Thread {
????Object o1;
????Object o2;
????public MyThread2(Object o1,Object o2){
????????this.o1 = o1;
????????this.o2 = o2;
????}
????public void run(){
????????synchronized (o2){
????????????try {
????????????????Thread.sleep(1000);
????????????} catch (InterruptedException e) {
????????????????e.printStackTrace();
????????????}
????????????synchronized (o1){
????????????}
????????}
????}
}