为了实现这种功能，可以借助object对象提供的wait(),notify(),notifyall();这三个方法不属于thread类，而是属于object类，但是这三个方法必须由同步监视器来调用，对于用synchronized修饰的同步方法该类的默认就是this就是同步监视器，所以直接调用这三个方法，对于synchronized修饰的同步代码块，是括号里面的对象才是同步监视器，必须该对象才能调用.

package Mytread;
import java.math.BigDecimal;
public class Acount {
private String account_name;//账户编号
private double money_sum;//账户余额
private boolean flag;//标志账户是否有钱
private double draw_money;//要取多少钱
public Acount(){}
public Acount(String account_name,double money_sum){
this.account_name=account_name;
this.money_sum=money_sum;
}
//返回账户余额
public double get_money_Sum(){
return this.money_sum;
}
//取钱操作
public synchronized void draw(double draw_money){
try {
if(!flag){
this.wait();
}else{
System.out.println(this.money_sum);
System.out.println(Thread.currentThread().getName()+" 取钱："+draw_money);
this.money_sum=this.money_sum-draw_money;
System.out.println(Thread.currentThread().getName()+"账户余额为："+this.money_sum);
flag=false;
notifyAll();
}
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
//存钱
public synchronized void deposit(double deposit_money){
try{
if(flag){
wait();
}else{
System.out.println(Thread.currentThread().getName()+"存款为："+deposit_money);
this.money_sum+=deposit_money;
System.out.println(Thread.currentThread().getName()+"总存款为："+this.money_sum);
flag=true;
notifyAll();
}
}catch(Exception e){
System.out.println(e.getMessage());
}
}
}

package Mytread;
public class deposit_money extends Thread{
private Acount acount;
private double deposit_money;//存取的钱数
public deposit_money(String name,Acount acount,double deposit_money){
super(name);
this.acount=acount;
this.deposit_money=deposit_money;
}
public void run(){
for(int i=0;i<100;i++){
acount.deposit(deposit_money);
}
}
}

package Mytread;

import java.math.BigDecimal;
import java.util.concurrent.locks.ReentrantLock;
public class Draw_money extends Thread{
private Acount acount;//模拟用户
private double draw_money;//模拟取钱数目
public Draw_money(){}
public Draw_money(String name,Acount acount,double draw_money){
super(name);
this.acount=acount;
this.draw_money=draw_money;
}
public void run(){
for(int i=0;i<100;i++){
acount.draw(draw_money);
}
}

}

package Mytread;
public class Bank_Test {
public static void main(String[] args){
Acount acc=new Acount("1234567", 0);
new Draw_money("取钱着",acc, 800).start();
new deposit_money("存钱着1", acc, 800).start();
new deposit_money("存钱着2", acc, 800).start();
new deposit_money("存钱着3", acc, 800).start();
}

}