脏读

先上一个例子

package com.louis.线程;

public class DirtyRead {
    private String username = "bjsxt";
    private String password = "123";

    public synchronized void setValue(String username, String password){

        this.username = username;
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        this.password = password;

        System.out.println("setValue最终结果：username = " + username + " , password = " + password);
    }

    public void getValue(){  //synchronized
        System.out.println("getValue方法得到：username = " + this.username + " , password = " + this.password);
    }


    public static void main(String[] args) throws Exception{

        final DirtyRead dr = new DirtyRead();
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                dr.setValue("z3", "456");
            }
        });
        t1.start();
        Thread.sleep(1000);

        dr.getValue();
    }
}

解决：在setvalue（）时，不希望getValue（）执行

package com.louis.线程;

public class DirtyRead {
    private String username = "bjsxt";
    private String password = "123";

    public synchronized void setValue(String username, String password){

        this.username = username;
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        this.password = password;

        System.out.println("setValue最终结果：username = " + username + " , password = " + password);
    }

    public synchronized void getValue(){  //synchronized
        System.out.println("getValue方法得到：username = " + this.username + " , password = " + this.password);
    }


    public static void main(String[] args) throws Exception{

        final DirtyRead dr = new DirtyRead();
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                dr.setValue("z3", "456");
            }
        });
        t1.start();
        Thread.sleep(1000);

        dr.getValue();
    }
}