实现深度拷贝的两种方法

最新推荐文章于 2025-06-25 08:30:00 发布

写bug时长三年

最新推荐文章于 2025-06-25 08:30:00 发布

阅读量4.1k

点赞数 1

CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/qq_34557770/article/details/89643879

本文深入探讨了深拷贝的两种实现方法：通过对象自身实现拷贝方法和利用序列化技术进行深拷贝。详细解释了如何在Java中对包含复杂对象结构的数据进行完全复制，避免引用共享导致的问题。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1.对象实现拷贝方法，对象内部的基本类型不用管，不涉及到地址

对象类型继续实现拷贝方法：

package calmcalmcalm;

import lombok.Data;

import java.util.Arrays;
import java.util.List;

/**
 * @author jinsong.Liang
 * @Description
 * @date 2019/4/28 18:10
 */
public class deepCopy2 {
    public static void main(String[] args) throws CloneNotSupportedException {
        Person person = new Person();
        person.setName("小李");
        person.setAge(20);
        GrandParent one = new GrandParent("小李爷爷", 80);
        GrandParent another = new GrandParent("小李奶奶", 77);
        person.setGrandParents(Arrays.asList(one,another));
        Person person2 = (Person) person.clone();
        person2.setName("小松");
        person2.setAge(21);
        person2.setGrandParents(Arrays.asList(new GrandParent("小松爷爷",81),new GrandParent("小松奶奶",77)));
        System.out.println(person+" "+person2);
    }
}

@Data
class Person implements Cloneable{
    private String name;
    private int age;
    private List<GrandParent> grandParents;

    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}

@Data
class GrandParent implements Cloneable{
    private String name;
    private int age;

    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

    public GrandParent() {
    }

    public GrandParent(String name, int age) {
        this.name = name;
        this.age = age;
    }
}

2.使用序列化直接写入流中再从流中读取用到了

ByteArrayOutputStream ByteArrayInputStream

ObjectOutputStream ObjectInputStream：

package calmcalmcalm;

import lombok.Data;

import java.io.*;
import java.util.Arrays;
import java.util.List;

/**
 * @author jinsong.Liang
 * @Description 串行化实现深拷贝
 * @date 2019/4/28 17:27
 */

public class deepCopy {
    public static void main(String[] args) {
        Student stu = new Student();
        stu.setName("小李");
        Parent one = new Parent("小李爸", 40);
        Parent another = new Parent("小李妈", 37);
        stu.setParents(Arrays.asList(one, another));
        try {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            ObjectOutputStream os = new ObjectOutputStream(out);
            os.writeObject(stu);
            ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
            ObjectInputStream is = new ObjectInputStream(in);
            Student object = (Student) is.readObject();
            object.setName("小松");
            object.setParents(Arrays.asList(new Parent("小松爸", 40), new Parent("小松妈", 36)));
            System.out.println(object + " " + stu);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

@Data
class Student implements Serializable {
    private static final long serialVersionUID = 1225886679045375224L;
    private String name;
    private List<Parent> parents;
}

@Data
class Parent implements Serializable {
    private static final long serialVersionUID = 3295359707477734908L;
    private String name;
    private int age;

    public Parent() {
    }

    public Parent(String name, int age) {
        this.name = name;
        this.age = age;
    }
}

Idea出现中文乱码：字符编码设置为GBK即可 convert方式而非reload方式

关于编码：

GBK存储：中文俩字节英文一个字节

UTF8 UTF16 UTF32是根据尽可能使用分配空间和直接分配较大的空间而产生的不同编码方式

UTF8存储 1-6字节 UTF16介于UTF8 和 UTF32之间 2字节或4字节 UTF32是4个字节存储