基本介紹

1. 原型模式(Prototype模式)是指：用原型實(shí)例指定創(chuàng)建對(duì)象的種類会前，并且通過(guò)拷 貝這些原型，創(chuàng)建新的對(duì)象 驶社。
2. 原型模式是一種創(chuàng)建型設(shè)計(jì)模式堵腹，允許一個(gè)對(duì)象再創(chuàng)建另外一個(gè)可定制的對(duì)象， 無(wú)需知道如何創(chuàng)建的細(xì)節(jié) 。
3. 工作原理是:通過(guò)將一個(gè)原型對(duì)象傳給那個(gè)要發(fā)動(dòng)創(chuàng)建的對(duì)象吁讨，這個(gè)要發(fā)動(dòng)創(chuàng)建 的對(duì)象通過(guò)請(qǐng)求原型對(duì)象拷貝它們自己來(lái)實(shí)施創(chuàng)建髓迎，即 對(duì)象.clone()。

深拷貝之普通重寫

復(fù)制一個(gè)對(duì)象建丧，連帶屬性的值復(fù)制出來(lái)排龄，屬性如果是引用類型，那么是一個(gè)地址翎朱，用了另外的空間橄维。

代碼實(shí)現(xiàn)（原型是重點(diǎn)）

原型類

package com.yuan.dp.prototype.domain;

public class People implements Cloneable {

    private String name;
    private int age;
    private Friend friend;

    public People() {
        super();
    }

    public People(String name, int age, Friend friend) {
        this.name = name;
        this.age = age;
        this.friend = friend;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

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

    public Friend getFriend() {
        return friend;
    }

    public void setFriend(Friend friend) {
        this.friend = friend;
    }

    /**
     * 第1種 深拷貝方法
     *
     * @return
     */
    @Override
    public People clone() {
        People people = null;
        try {
            //1.調(diào)用淺拷貝將所有屬性的值拷貝過(guò)來(lái)
            people = (People) super.clone();
            //2.調(diào)用引用類型屬性的克隆方法覆蓋當(dāng)前的屬性值
            people.friend = friend.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return people;
    }

    @Override
    public String toString() {
        return "People{" +
                "name='" + name +
                ", age=" + age +
                ", friend=" + friend.hashCode() +
                '}';
    }
}

引用類型屬性類

package com.yuan.dp.prototype.domain;

import java.io.Serializable;

public class Friend implements Cloneable, Serializable {
    public String name ;
    public String hobby ;

    /**
     * 如果沒(méi)有引用類型 就用淺拷貝 默認(rèn)的
     * @return
     * @throws CloneNotSupportedException
     */
    @Override
    protected Friend clone() throws CloneNotSupportedException {
        Friend friend = (Friend) super.clone();
        return friend;
    }
}

測(cè)試

package com.yuan.dp.prototype;

import com.yuan.dp.prototype.domain.Friend;
import com.yuan.dp.prototype.domain.People;

/**
 * 深拷貝 拷貝
 *
 * @author Yuan-9826
 */
public class Prototype_2 {
    public static void main(String[] args) {
        Friend friend = new Friend();
        People yuan_1 = new People("yuan", 18, friend);
        System.out.println("yuan_1 = " + yuan_1);
        //yuan_1 = People{name='yuan, age=18, friend=42121758}
        People yuan_2 = yuan_1.clone();
        System.out.println("yuan_2 = " + yuan_2);
        //yuan_2 = People{name='yuan, age=18, friend=20671747}
        System.out.println(yuan_1 == yuan_2);
        //false

    }
}