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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);	}}

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);	}}

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