java模拟线程死锁

public class Main{

    /*模拟死锁
     * 
     * PersonA要拿到B才把A给B
     * PersonB要拿到A才把B给A
     * 
     * 
     * 
     */
    
    public static void main(String[] args) {
        new Thread(new Run(true)).start();
        new Thread(new Run(false)).start();
    }

}

class PersonA{
    
    public void say(){
        System.out.println("A说：把B给我");
    }
    
    public void getB(){
        System.out.println("A得到了B的东西");
    }
}

class PersonB{
    public void say(){
        System.out.println("B说：把A给我");
    }
    
    public void getA(){
        System.out.println("B得到了A的东西");
    }
}

class Run implements Runnable{
    
    //一定要是静态的对象
    static PersonA a = new PersonA();
    static PersonB b = new PersonB();
    private boolean aGiveB;        //是否是A给B
    
    public Run(boolean aGiveB){
        this.aGiveB = aGiveB;
    }
    
    @Override
    public void run() {
        if(aGiveB){
            synchronized (b) {
                b.say();
                try {
                    Thread.sleep(500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                synchronized (a) {
                    System.out.println("a把A给了b");
                    b.getA();
                }
            }
        }else{
            synchronized (a) {
                a.say();
                try {
                    Thread.sleep(500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                synchronized (b) {
                    System.out.println("b把B给了a");
                    a.getB();
                }
            }
        }
    }
    
}