【Java对象实例与文件之间互转】

自定义对象

package com.example.demo;

import java.io.Serializable;

/**
 * 自定义对象，不实现Serializable，序列化时会报错
 */
class User implements Serializable {

    private static final long serialVersionUID = 686362938982330454L;
    String name;
    int age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

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

class DemoApplicationTests {

    public static final String filepath = "C:\\Users\\seczone\\Desktop\\test3.class";

    /**
     * 对象实例转为文件
     */
    @Test
    void contextLoads() throws Exception {
        Map<Object, Object> map = new HashMap<>();
        map.put("字符", "1");
        map.put("数字", 1);
        map.put("char", '1');
        map.put("boolean", true);

        List<Object> list = new ArrayList<>();
        list.add(map);
        list.add("list");

        User user = new User();
        user.setName("xsp");
        user.setAge(18);

        FileOutputStream fos = new FileOutputStream(filepath);
        ObjectOutputStream objectOutputStream = new ObjectOutputStream(fos);
        objectOutputStream.writeObject(map);
        objectOutputStream.writeObject(list);
        objectOutputStream.writeObject(user);
        objectOutputStream.close();
        fos.close();
    }

    /**
     * 文件转为对象实例
     */
    @Test
    void test() throws Exception {
        FileInputStream fis = new FileInputStream(filepath);
        ObjectInputStream ois = new ObjectInputStream(fis);
        System.out.println(ois.readObject());
        System.out.println(ois.readObject());
        System.out.println(ois.readObject());
        ois.close();
        fis.close();
    }
    
}
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