Java多线程的交替执行

   读完Think In Java的多线程,深有感悟，花了1个小时，写了一个多线程交替执行程序，大家可以参考，如有好的意见，请提出，谢谢!
package com.thread;

public class ThreadTest implements Runnable {


public void run() {
int j = 0;
while (true) {

try {
synchronized (this) {
if (j == 5) {
j = 0;
Tmp.getA().setOnoff(true);
Tmp.getA().Notify();
wait();
}
Thread.sleep(100);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("XX+++"+j);
j++;
}
}



public synchronized void Notify() {
notify();
}

public static void main(String[] args) {

ThreadA A = new ThreadA();
Thread testA = new Thread(A);
testA.start();

ThreadTest B = new ThreadTest();
Thread testB = new Thread(B);
testB.start();

Tmp tmp = new Tmp();
tmp.setB(B);
tmp.setA(A);

}

}

class Tmp {
private static ThreadTest B;
private static ThreadA A;

public static ThreadA getA() {
return A;
}

public static void setA(ThreadA a) {
A = a;
}

public static ThreadTest getB() {
return B;
}

public static void setB(ThreadTest b) {
B = b;
}
}

class ThreadA implements Runnable {

boolean Onoff = false;

public boolean setOnoff(boolean LnKai) {
return Onoff = LnKai;
}

public synchronized void Notify() {
notify();
}


public void run() {
int j = 0;
while (true) {

while (Onoff) {

try {
synchronized (this) {
if (j == 5) {
j=0;
Onoff = false;
Tmp.getB().Notify();
wait();
}
Thread.sleep(100);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("YY---"+j);
j++;

}
}

}
}

结果:
XX+++0
XX+++1
XX+++2
XX+++3
XX+++4
YY---0
YY---1
YY---2
YY---3
YY---4
XX+++0
XX+++1
XX+++2
XX+++3
XX+++4
YY---0
YY---1
YY---2
YY---3
YY---4
XX+++0
XX+++1
XX+++2
XX+++3
XX+++4
YY---0
YY---1
YY---2
YY---3
YY---4