原型模式(创建型模式)

左手的ㄟ右手 2022-07-16 10:47 195阅读 0赞

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由上边的类图可以看出，原型模式总共有三种角色，

1.客户角色：该角色提出创建对象的请求。

2.抽象原型:该角色是一个抽象角色,通常是有一个Java接口或者是抽象类实现

3.具体原型:该角色是被复制的对象,必须实现抽象原型接口。

原型模式有以下的一些优点:

1.性能优良,原型模式是在内存二进制流的复制，要比直接new 一个对象性能好。

2.可以逃避构造函数的约束,直接在内存中复制。

下面给出一个原型模式的例子:

import java.util.Random;
    public class ClientDemo 
    {
    	private static int MAX_COUNT=6;
    	
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		int i=0;
    		//定义一个邮件对象
    		Mail mail=new Mail("某商场周末活动","凡是在五一期间购物满100元的客户都有抽奖机会!.....");
    		mail.setTail("解释权归某商场所有");
    		while(i<MAX_COUNT)
    		{
    			Mail cloneMail=mail.clone();
    			cloneMail.setAppellation(getRandString(5)+"先生(女士)");
    			cloneMail.setReceiver(getRandString(5)+"@"+getRandString(8)+".com");
    			sendMail(cloneMail);
    			i++;
    		}
    	}
    
    	private static void sendMail(Mail cloneMail) {
    		// TODO Auto-generated method stub
    		System.out.println("标题:"+cloneMail.getSubject()+"\t收件人:"+cloneMail.getReceiver()+"\t......发送成功!");
    	}
    
    	private static String getRandString(int maxLength) 
    	{
    		// TODO Auto-generated method stub
    		String source="abcdefghijklmnopqrstuvwxyz";
    		StringBuffer sb=new StringBuffer();
    		Random rand=new Random();
    		for(int i=0;i<maxLength;i++){
    			sb.append(source.charAt(rand.nextInt(source.length())));
    			
    		}
    		return sb.toString();
    	}
    
    }

public class Mail implements Cloneable {
    private String receiver;
    private String subject;
    private String appellation;
    private String contxt;
    private String tail;
    public Mail(String subject, String contxt) {
    	super();
    	this.subject = subject;
    	this.contxt = contxt;
    }
    public String getReceiver() {
    	return receiver;
    }
    public void setReceiver(String receiver) {
    	this.receiver = receiver;
    }
    public String getSubject() {
    	return subject;
    }
    public void setSubject(String subject) {
    	this.subject = subject;
    }
    public String getAppellation() {
    	return appellation;
    }
    public void setAppellation(String appellation) {
    	this.appellation = appellation;
    }
    public String getContxt() {
    	return contxt;
    }
    public void setContxt(String contxt) {
    	this.contxt = contxt;
    }
    public String getTail() {
    	return tail;
    }
    public void setTail(String tail) {
    	this.tail = tail;
    }
    //克隆方法
    public Mail clone(){
    	Mail mail=null;
    	try 
    	{
    		mail =(Mail) super.clone();
    	} 
    	catch (CloneNotSupportedException e) 
    	{
    		// TODO Auto-generated catch block
    		e.printStackTrace();
    	}
    	return mail;
    }
    
    }

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