原型模式

原型模式（克隆模式）：1通过new产生一个对象需要非常繁琐的数据准备或访问权限，则可以使用原型模式

2 以某个对象为原型，复制新的对象。避免了重新执行构造过称步骤

3 克隆出的新对象不会改变原型对象，然后再修改克隆的值；new创建的对象属性采用的是默认值

实现：Cloneable接口和Clone()方法

浅克隆：复制之后，若s1的属性改变，则s2的属性也会改变

package prototype;

import java.util.Date;

public class Sheep implements Cloneable {
	private String name;
	private Date birthday;

	@Override
	protected Object clone() throws CloneNotSupportedException {
		Object obj = super.clone(); // 直接调用Object对象的clone()方法；
		return obj;
	}

	public String getName() {
		return name;
	}

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

	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}

	public Sheep(String name, Date birthday) {
		super();
		this.name = name;
		this.birthday = birthday;
	}

	public Sheep() {

	}

}

package prototype;

import java.util.Date;

//测试原型系统（浅克隆）
public class Client {
	public static void main(String[] args) throws Exception {
		Date d = new Date(12312321331L);
		Sheep s1 = new Sheep("多利", d);
		System.out.println(s1);
		System.out.println(s1.getName());
		System.out.println(s1.getBirthday());

		d.setTime(2343243223L);
		System.out.println(s1.getBirthday());

		Sheep s2 = (Sheep) s1.clone();
		System.out.println(s2);
		System.out.println(s2.getName());
		System.out.println(s2.getBirthday());

	}

}

深克隆（联同属性一起克隆）：即使s1的属性改变，复制之后s2的属性不会变

package prototype;

import java.util.Date;

public class Sheep2 implements Cloneable {
	private String name;
	private Date birthday;

	@Override
	protected Object clone() throws CloneNotSupportedException {
		Object obj = super.clone(); // 直接调用Object对象的clone()方法；

		// 添加以下代码实现深复制（deep Clone）
		Sheep2 s = (Sheep2) obj;
		s.birthday = (Date) this.birthday.clone();// 把属性也进行复制
		return obj;
	}

	public String getName() {
		return name;
	}

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

	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}

	public Sheep2(String name, Date birthday) {
		super();
		this.name = name;
		this.birthday = birthday;
	}

	public Sheep2() {

	}

}

package prototype;

import java.util.Date;

//原型模式（深复制）
public class Client2 {

	public static void main(String[] args) throws Exception {
		Date d = new Date(12312321331L);
		Sheep2 s1 = new Sheep2("多利", d);
		Sheep2 s2 = (Sheep2) s1.clone();// 实现深复制。s2对象的birthday是一个新对象

		System.out.println(s1);
		System.out.println(s1.getName());
		System.out.println(s1.getBirthday());

		d.setTime(2343243223L);
		System.out.println(s1.getBirthday());

		System.out.println(s2);
		System.out.println(s2.getName());
		System.out.println(s2.getBirthday());

	}

}