java多线程脏读演式

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public class Account {
String name;
double balance; //余额

public synchronized void set(String name,double balance){ //set 方法写入余额
this.name = name;

try {
Thread.sleep(2000); //中断这个线程扩大问题,不然执行时间短看不出效果
} catch (InterruptedException e) {
e.printStackTrace();
}
this.balance = balance;
}
public /*synchronized*/ double getBalance(String name){ //读取余额不加锁会产生脏读,解决方法就是读时也加锁!
return this.balance;
}

public static void main(String[] args) {
Account a = new Account();
new Thread(()->a.set("zhansan",100.00)).start(); //执行线程,"()->a.set("zhansan",100.00)",java1.8才支持,开辟一个新线程执行a的set方法.

try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(a.getBalance("zhangsan")); //第一次读取时还未写入~读取到默认值. 执行结果 : 0.0
try {
TimeUnit.SECONDS.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(a.getBalance("zhangsan")); //执行结果 : 100.00
}
}

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