多线程案例：银行取钱

//不安全取钱?

//两个人去银行取钱，账户

//银行取钱：给账户上锁

public class UnsafeBank {

????public static void main(String[] args) {

//账户

Account3 account = new Account3(1000,"生活费");

Drawing you = new Drawing(account,500,"你");

Drawing son = new Drawing(account,1000,"儿子");

????????you.start();

????????son.start();

????}

}

//账户

class Account3{

int money; //余额

????String name;

????public Account3(int money, String name) {

????????this.money = money;

????????this.name = name;

????}

}

//银行：模拟取款

class Drawing extends Thread{

Account3 account;//账户

????int drawingMoney;

//现在手里还有多少钱

????int nowMoney;

????public Drawing(Account3 account,int drawingMoney,String name){

????????super(name);

????????this.account=account;

????????this.drawingMoney=drawingMoney;

????}

//取钱

//synchronized默认锁this.

????@Override

????public ?void run(){

????????synchronized (account){

//判断有没有钱

????????????if (account.money-drawingMoney<0){

System.out.println(Thread.currentThread().getName()+"钱不够取不了");

????????????????return;

????????????}

try {//sleep放大问题的发生性

????????????????Thread.sleep(1000);

????????????} catch (InterruptedException e) {

????????????????e.printStackTrace();

????????????}

//卡里的余额=余额-你取的钱

????????????account.money=account.money-drawingMoney;

//你手里的钱

????????????nowMoney=nowMoney+drawingMoney;

System.out.println(account.name+"余额为："+account.money);

????????????//Thread.currentThread().getName()=this.getName()

System.out.println(this.getName()+"手里的钱："+nowMoney);

????????}

????}

}