不安全线程取钱
1 package 多线程练习; 2 3 import com.sun.javafx.sg.prism.web.NGWebView; 4 5 import java.math.BigDecimal; 6 7 /* 8 模拟两个人同时取钱的情况 9 */ 10 public class UnSafeAccount { 11 public static void main(String[] args) { 12 Bank bank = new Bank("12345", new BigDecimal("100")); 13 WithDrawMoney xiaoming = new WithDrawMoney(bank, new BigDecimal("50"), "小明"); 14 WithDrawMoney xiaomingxf = new WithDrawMoney(bank, new BigDecimal("100"), "小明媳妇"); 15 xiaoming.start(); 16 xiaomingxf.start(); 17 18 } 19 } 20 21 22 /* 23 银行类 24 */ 25 class Bank { 26 String cardNumer; // 卡号 27 BigDecimal balance; // 余额 小tip:Java中用BigDecimal 来表示金钱类型 28 29 public Bank(String cardNumer, BigDecimal balance) { 30 this.cardNumer = cardNumer; 31 this.balance = balance; 32 } 33 34 } 35 36 class WithDrawMoney extends Thread { 37 // 模拟正式环境全部私有 38 Bank bank; 39 BigDecimal nowMoney = new BigDecimal("0"); // 手里的钱 40 BigDecimal drawMoney; // 取走的钱 41 42 // 构造方法 43 public WithDrawMoney(Bank bank, BigDecimal drawMoney, String name) { 44 super(name); // 调用父类的只能用在第一行 45 this.bank = bank; 46 this.drawMoney = drawMoney; 47 } 48 49 @Override 50 public void run() { 51 if (bank.balance.subtract(drawMoney).compareTo(BigDecimal.ZERO) == -1) { 52 System.out.println(this.getName() + " 钱不够了，取钱失败"); // 线程类中this.getName() == Thread.currentThread.getName() 53 return; 54 } 55 56 try { 57 Thread.sleep(500); 58 } catch (InterruptedException e) { 59 e.printStackTrace(); 60 } 61 62 nowMoney = nowMoney.add(drawMoney); // 手里的钱 63 bank.balance = (bank.balance.subtract(drawMoney)); // 卡上余额 subtract 减法 add 加法 64 System.out.println(this.getName() + " 手里有 " + nowMoney + "钱"); 65 System.out.println("卡上余额：" + bank.balance); 66 } 67 68 69 }
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