GoF23 原型模式学习笔记_gof23 笔记-优快云博客

本文链接：https://blog.youkuaiyun.com/Aetherzzz/article/details/115446241

本文详细介绍了Java中的原型模式，包括如何实现Cloneable接口和重写clone方法。通过示例代码展示了浅拷贝和深拷贝的区别，浅拷贝仅复制对象引用，而深拷贝则进行实际内容的复制。此外，还讨论了原型模式在SpringBean创建和工厂模式中的应用。

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GoF23 原型模式学习笔记

 1. 实现Cloneable接口
 2. 重写clone方法

应用场景：
 1. Spring Bean 的创建：单例模式、原型模式
 2. 与工厂模式一起使用，代替 new

浅拷贝

代码中表现为cloneVideo的publishTime只是指向了原video的publishTime

package prototype.shallow;

import java.util.Date;

public class Video implements Cloneable {
	private String name;
	private Date publishTime;

	public Video(String name, Date publishTime) {
		this.name = name;
		this.publishTime = publishTime;
	}

	public Video() {
	}

	public String getName() {
		return name;
	}

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

	public Date getPublishTime() {
		return publishTime;
	}

	public void setPublishTime(Date publishTime) {
		this.publishTime = publishTime;
	}

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

	@Override
	public String toString() {
		return "Video [name=" + name + ", publishTime=" + publishTime + "]";
	}

}

package prototype.shallow;

import java.util.Date;

public class Main {

	public static void main(String[] args) throws CloneNotSupportedException {
		Date date = new Date();
		Video video = new Video("VideoName", date);
		Video cloneVideo = (Video)video.clone();
		System.out.println(video);
		System.out.println(cloneVideo);
		
		date.setTime(1231241);
		
		System.out.println(video);
		System.out.println(cloneVideo);
	}

}

在这里插入图片描述

深拷贝

package prototype.deep;

import java.util.Date;

public class Video implements Cloneable {
	private String name;
	private Date publishTime;

	public Video(String name, Date publishTime) {
		this.name = name;
		this.publishTime = publishTime;
	}

	public Video() {
	}

	public String getName() {
		return name;
	}

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

	public Date getPublishTime() {
		return publishTime;
	}

	public void setPublishTime(Date publishTime) {
		this.publishTime = publishTime;
	}

	@Override
	protected Object clone() throws CloneNotSupportedException {
		Object obj = super.clone();
		Video v = (Video)obj;
		v.publishTime = (Date)this.publishTime.clone();
		return obj;
	}

	@Override
	public String toString() {
		return "Video [name=" + name + ", publishTime=" + publishTime + "]";
	}

}

package prototype.deep;

import java.util.Date;

public class Main {

	public static void main(String[] args) throws CloneNotSupportedException {
		Date date = new Date();
		Video video = new Video("VideoName", date);
		Video cloneVideo = (Video)video.clone();
		System.out.println(video);
		System.out.println(cloneVideo);
		
		date.setTime(1231241);
		
		System.out.println(video);
		System.out.println(cloneVideo);
	}

}

在这里插入图片描述