对象序列化：把Java对象写入到文件中去

package com.itheima.d3;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;

public class Test1 {
    public static void main(String[] args) {
        try(
                //2、创建一个对象字节输出流包装原始的字节输出流
                ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("IO/src/itheima11.txt"));
                ) {

            //1、创建一个Java对象
            User u = new User("rch", "任朝晖", 18, "rch041126");
            //3、序列化对象到文件中去
            oos.writeObject(u);
            System.out.println("序列化对象成功");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

 注意：对象如果需要序列化，必须实现序列化接口

package com.itheima.d3;

import java.io.Serializable;

//注意：对象如果需要序列化，必须实现序列化接口
public class User implements Serializable {
    private String loginName;
    private String userName;
    private int age;
    //transient 这个成员变量不参与序列化 
    private transient String passWord;

    public User() {
    }

    public User(String loginName, String userName, int age, String passWord) {
        this.loginName = loginName;
        this.userName = userName;
        this.age = age;
        this.passWord = passWord;
    }

    public String getLoginName() {
        return loginName;
    }

    public void setLoginName(String loginName) {
        this.loginName = loginName;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getPassWord() {
        return passWord;
    }

    public void setPassWord(String passWord) {
        this.passWord = passWord;
    }

    @Override
    public String toString() {
        return "User{" +
                "loginName='" + loginName + '\'' +
                ", userName='" + userName + '\'' +
                ", age=" + age +
                ", passWord='" + passWord + '\'' +
                '}';
    }
}

对象饭序列化：把文件里的Java对象读取出来

package com.itheima.d3;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;

public class Test3 {
    public static void main(String[] args) {
        try(
                //1、创建一个对象字节输入流管道，包装 低级的字节输入流与源文件接通
                ObjectInputStream ois =
                        new ObjectInputStream(new FileInputStream("IO/src/itheima11.txt"));
                ) {

           User u = (User) ois.readObject();
            System.out.println(u);
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}