写两个线程，一个线程打印 1~52，另一个线程打印字母A-Z。打印顺序为12A34B56C……5152Z

package com.test7;

public class Test16_1 {

public static void main(String[] args) {
//创建一个打印机
Printer aprinter=new Printer();
//同步该打印机输出
NumPrinter np=new NumPrinter(aprinter);
AlpPrinter ap=new AlpPrinter(aprinter);
np.start();
ap.start();
}

}
class Printer
{
//标识该打印数字还是字母？False打印数字，True打印字母，木人先打印数字.
private boolean flag=false;
//打印数字
public synchronized void print1()
{
for (int i=0;i<52;)
{
if (flag==false)
{
System.out.print((i+1));
System.out.print((i)+2);
//只有成功打印，i才会自增，所以没有放在for循环里
i++;
i++;
//重新将flag置为true，等待输出字母
flag=true;
//激活其它线程
this.notifyAll();
}
else
{
try {
//如果为true，则说明不应输出数字，等待输出
this.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}
}
//输出字母打印机，同数字打印机方法
public synchronized void print2()
{
for(char c='A';c<='Z';)
{
if (flag==true)
{
System.out.print(c);
flag=false;
c++;
this.notifyAll();
}
else
{
try {
this.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}
}
}
//创建数字打印机线程
class NumPrinter extends Thread
{
private Printer aprinter=new Printer();

public NumPrinter(Printer aprinter)
{
this.aprinter=aprinter;
}

public void run() {
// TODO Auto-generated method stub
aprinter.print1();
}
}
//创建字母打印机线程
class AlpPrinter extends Thread
{

private Printer aprinter=new Printer();

public AlpPrinter(Printer aprinter)
{
this.aprinter=aprinter;
}

public void run() {
// TODO Auto-generated method stub
aprinter.print2();
}
}