【Java】 Java中的浅拷贝和深拷贝

先抛出结论:

  浅拷贝是引用拷贝,A对象拷贝B以后,A对象和B对象指向同一块内存地址,改变A对象的属性值会触发B对象属性的改变,有安全风险

  深拷贝是对象拷贝,A对象拷贝B以后,A对象和B对象指向不同的额内存地址,改变A对象的属性值不会触发B对象属性的改变,无安全风险,但是成本较高

  如何实现深拷贝:

    实现Clonable接口,重写clone方法

代码如下

package com.gabriel.stage.vo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.NoArgsConstructor;

/**
 * @author: Gabriel
 * @date: 2020/3/12 0:00
 * @description 测试类
 */
public class TestTransfer {
    public static void main(String[] args) throws CloneNotSupportedException {
        //浅拷贝 拷贝引用
        Student A1 = new Student(1,"张三");
        Student B1 = A1;
        B1.age=2;
        System.out.println(A1);
        System.out.println(B1);
        System.err.println("============华丽的分割线=============");
        //深拷贝 拷贝内存地址
        Student A2 = new Student(1, "张三");
        Student B2 = (Student) A2.clone();
        B2.age = 2;
        System.out.println(A2);
        System.out.println(B2);

    }
}

@Data
@AllArgsConstructor
@NoArgsConstructor
@EqualsAndHashCode
class Student implements Cloneable{

    int age;
    String name;

    /**
     * 深拷贝实现Cloneable接口
     * @return
     * @throws CloneNotSupportedException
     */
    @Override
    public Object clone() throws CloneNotSupportedException {
        Student stu = null;
        try{
            stu = (Student)super.clone();
        }catch(CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return stu;

    }
}

 

posted @ 2020-03-13 11:58  听风是雨  阅读(452)  评论(0编辑  收藏  举报
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