《Java基础知识》Java 浅拷贝与深拷贝1

原创已于 2022-06-30 17:33:44 修改 · 180 阅读

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#java #.net #开发语言

于 2022-06-30 17:33:37 首次发布

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本文通过实例代码解析了Java中浅拷贝的概念，展示了如何实现对象的浅拷贝。在示例中，年龄作为基本类型在浅拷贝后保持独立，而引用类型的DogSchool对象地址被共享，导致修改其属性会影响到拷贝后的对象。同时，文章解释了String在浅拷贝下不受影响的原因，因其被final修饰，修改其实质是创建新的字符串常量。

前言

在学习ArrayList的时候，发现ArrayList继承了Cloneable接口，于是就想着需要了解一下该接口是什么作用。

浅拷贝

我们先写一段代码，来看看什么是浅拷贝

public class DogSchool {
    public String address;

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

public class Dog implements Cloneable{
    public int age;
    public String name;
    public DogSchool dogSchool;

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

    public int getAge() {
        return age;
    }

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

    public String getName() {
        return name;
    }

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

    public DogSchool getDogSchool() {
        return dogSchool;
    }

    public void setDogSchool(DogSchool dogSchool) {
        this.dogSchool = dogSchool;
    }

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

public class CloneTest {

    public static void main(String[] args) throws CloneNotSupportedException {
        /*************** 设置好原对象信息 *****************/
        Dog dogSource = new Dog(12,"li");
        DogSchool dogSchool = new DogSchool();
        dogSchool.setAddress("hangzhou");
        dogSource.setDogSchool(dogSchool);

        /*************** 进行对象拷贝，并且修改原对象的值 *****************/
        Dog dogTarget = (Dog) dogSource.clone();
        dogSource.getDogSchool().setAddress("shanghai");
        dogSource.setAge(14);

        System.out.println("dogSource.age:"+dogSource.getAge());
        System.out.println("dogSource.dogSchool.address:"+dogSource.getDogSchool().getAddress());
        System.out.println("dogTarget.age:"+dogTarget.getAge());
        System.out.println("dogTarget.dogSchool.address:"+dogTarget.getDogSchool().getAddress());
        System.out.println("dogTarget.dog:"+dogSource.getDogSchool());
        System.out.println("dogTarget.dog:"+dogTarget.getDogSchool());
    }
}

运行结果：