//本题出现死锁的情况 是一种假设：如果符合预期（A给a加了锁，在等待b;B给b加了锁，在等待a），则会出现死锁；否则，不会。

class AThread implements Runnable{

@Override

public void run() {

synchronized (DeadLock.resource_a) {

System.out.println("A线程：已经给resource-a加了锁");

try {

Thread.sleep((long)(Math.random()*3000) );

} catch (InterruptedException e) {

e.printStackTrace();

}

synchronized (DeadLock.resource_b){//尝试给B加锁

System.out.println("A线程：等待给resource-b加锁...");

}

}

}

}

class BThread implements Runnable{

@Override

public void run() {

synchronized (DeadLock.resource_b) {

System.out.println("B线程：已经给resource-b加了锁");

try {

Thread.sleep((long)(Math.random()*3000) );

} catch (InterruptedException e) {

e.printStackTrace();

}

synchronized (DeadLock.resource_a){

System.out.println("B线程：等待给resource-a加锁...");

}

}

}

}

public class DeadLock {

static String resource_a = "resource-a" ;

static String resource_b = "resource-b" ;

public static void main(String[] args) {

Thread A = new Thread(new AThread());

Thread B = new Thread(new BThread());

A.start();

B.start();

}

}