TransientTest.java

package com.github.chapter3;

import java.io.*;

/**
 * 使用transient关键字不序列化某个变量
 * 注意读取的时候，读取数据的顺序一定要和存放数据的顺序保持一致
 * 1）一旦变量被transient修饰，变量将不再是对象持久化的一部分，该变量内容在序列化后无法获得访问。
   2）transient关键字只能修饰变量，而不能修饰方法和类。注意，本地变量是不能被transient关键字修饰的。变量如果是用户自定义类变量，则该类需要实现Serializable接口。
   3）被transient关键字修饰的变量不再能被序列化，一个静态变量不管是否被transient修饰，均不能被序列化。
 * Created by jhys on 2018/7/20
 */
public class TransientTest {
    public static void main(String[] args) {
        User user = new User();
        user.setUsername("Alexia");
        user.setPasswd("123456");

        System.out.println("read before Serializable: ");
        System.out.println("username: " + user.getUsername());
        System.err.println("password: " + user.getPasswd());

        try {
            ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream("D:/user.txt"));
            os.writeObject(user);
            os.flush();
            os.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            ObjectInputStream is = new ObjectInputStream(new FileInputStream("D:/user.txt"));
            user = (User) is.readObject();
            is.close();

            System.out.println("\nread after Serializable: ");
            System.out.println("username: " + user.getUsername());
            System.err.println("password: " + user.getPasswd());
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

    }
}

/**
 * https://blog.csdn.net/felcon/article/details/51839453 maven项目改变jdk版本
 */
class User implements Serializable {
    private static final long serialVersionUID = -4679557854112699643L;

    private String username;
    private transient String passwd;

    public static long getSerialVersionUID() {
        return serialVersionUID;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPasswd() {
        return passwd;
    }

    public void setPasswd(String passwd) {
        this.passwd = passwd;
    }
}