14_synchronized深入

package com.higgin.part4;

/**
 * 在我们对一个对象的方法加锁的时候，需要考虑业务的整体性。
 * 本例子中的setValue或getValue必须同时加上synchronized同步关键字，办证业务的原子性，不然会出现业务错误 
 */
public class DirtyRead {
    private String username="zhangsan";
    private String password="123";
    
    public synchronized void setValue(String username,String password){
        this.username=username;
        try {
            Thread.sleep(2000);   //延时2秒
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        this.password=password;
        System.out.println("setValue最终结果【 username = "+username+", password = "+password + "】");
    }
    
    /**
     * 加和不加synchronized有区别
     */
    public void getValue(){
        System.out.println("getValue最终结果【 username = "+username+", password = "+password + "】");
    }
    
    public static void main(String[] args) throws InterruptedException {
        final DirtyRead dr = new DirtyRead();
        
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                dr.setValue("lisi", "456");
            }
        });
        t1.start();   //t1线程去设置值
        Thread.sleep(1000);
        dr.getValue();    //相当于main线程去读取值
    }
}