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1.传统方式解决克隆羊问题

1.问题描述

2.类图

3.目录结构

4.代码实现

1.Sheep.java

package com.sun.tradition;/*** Description:* @Author sun* @Create 2024/5/28 19:26* @Version 1.0*/
public class Sheep {private String name;private int age;private String color;public Sheep(String name, int age, String color) {this.name = name;this.age = age;this.color = color;}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 String getColor() {return color;}public void setColor(String color) {this.color = color;}@Overridepublic String toString() {return "Sheep{" +"name='" + name + '\'' +", age=" + age +", color='" + color + '\'' +'}';}
}

2.Client.java

package com.sun.tradition;/*** Description: 使用传统的方式复制十只羊* @Author sun* @Create 2024/5/28 19:26* @Version 1.0*/
public class Client {public static void main(String[] args) {Sheep sheep = new Sheep("tom", 1, "白色");Sheep sheep1 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());Sheep sheep2 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());Sheep sheep3 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());Sheep sheep4 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());Sheep sheep5 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());Sheep sheep6 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());Sheep sheep7 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());Sheep sheep8 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());Sheep sheep9 = new Sheep(sheep.getName(), sheep.getAge(), sheep.getColor());System.out.println(sheep);}
}

5.优缺点分析

2.原型模式解决克隆羊问题（浅拷贝）

1.基本介绍

2.类图

3.目录结构

4.代码实现

1.Sheep.java 实现Cloneable接口的clone方法，使用原型模式来实现克隆

package com.sun.improve;/*** Description: 实现Cloneable接口的clone方法，使用原型模式来实现克隆* @Author sun* @Create 2024/5/28 19:26* @Version 1.0*/
public class Sheep implements Cloneable{private String name;private int age;private String color;public Sheep(String name, int age, String color) {this.name = name;this.age = age;this.color = color;}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 String getColor() {return color;}public void setColor(String color) {this.color = color;}@Overridepublic String toString() {return "Sheep{" +"name='" + name + '\'' +", age=" + age +", color='" + color + '\'' +'}';}@Overrideprotected Sheep clone() throws CloneNotSupportedException {return (Sheep) super.clone();}
}

2.Client.java

package com.sun.improve;/*** Description: 原型模式的客户端* @Author sun* @Create 2024/5/28 19:43* @Version 1.0*/
public class Client {public static void main(String[] args) throws CloneNotSupportedException {Sheep sheep = new Sheep("tom", 1, "白色");Sheep clone = sheep.clone();Sheep clon2 = sheep.clone();Sheep clon3 = sheep.clone();Sheep clon4 = sheep.clone();System.out.println(clone);}
}

3.原型模式在Spring框架中的源码分析

1.基本介绍

2.解释

• 在Spring中配置一个bean的时候，有一个scope属性可以选择配置prototype（原型模式）
• 当配置了这个参数，每次getBean的时候就相当于使用原型模式创建了一个新的对象，然后将原对象的属性浅拷贝到这个新的对象

4.深拷贝

1.默认的原型模式为浅拷贝

1.在Sheep.java中添加一个引用类型的数组

2.在Client.java测试克隆的羊和原来的羊的属性是不是一个数组

3.结果表明，默认的原型模式克隆出来的对象，会将引用类型的属性指向原型的属性，共享内存空间，也就是浅拷贝

2.浅拷贝与深拷贝

1.浅拷贝

2.深拷贝

5.实现深拷贝的两种方式

1.重写clone方法实现深拷贝

1.DeepCloneableTarget.java

package com.sun.deepcopy01;import java.io.Serializable;/*** Description: 要被深拷贝的对象，内部含有引用类型* @Author sun* @Create 2024/5/28 20:20* @Version 1.0*/
public class DeepCloneableTarget implements Serializable, Cloneable {public static final long serialVersionUID = 1L;private String name;private int[] arr; // 引用类型需要手动拷贝一份public DeepCloneableTarget(String name, int[] arr) {this.name = name;this.arr = arr;}/*** 重写克隆方法，使当前对象可以完成深拷贝* @return* @throws CloneNotSupportedException*/@Overrideprotected DeepCloneableTarget clone() throws CloneNotSupportedException {// 首先调用一次父类的克隆方法，浅拷贝一份当前对象DeepCloneableTarget clone = (DeepCloneableTarget) super.clone();// 目前的clone对象的arr是浅拷贝，所以需要将其手动拷贝一份int[] copyArr = new int[arr.length];if (arr != null) {int j = 0;for (int i : arr) {copyArr[j ++] = i;}}// 重新设置一下拷贝后的数组clone.arr = copyArr;return clone;}public int[] getArr() {return arr;}
}

2.Client.java

package com.sun.deepcopy01;import java.util.Arrays;/*** Description: 原型模式的客户端* @Author sun* @Create 2024/5/28 19:43* @Version 1.0*/
public class Client {public static void main(String[] args) throws CloneNotSupportedException {DeepCloneableTarget deepCloneableTarget = new DeepCloneableTarget("sunxiansheng", new int[]{1, 2, 3});DeepCloneableTarget clone = deepCloneableTarget.clone();// 测试深拷贝System.out.println(deepCloneableTarget.getArr() == clone.getArr());System.out.println(Arrays.toString(deepCloneableTarget.getArr()));System.out.println(Arrays.toString(clone.getArr()));}
}

3.结果

2.对象序列化实现深拷贝（推荐）

1.DeepCloneableTarget.java

package com.sun.deepcopy02;import java.io.*;/*** Description: 要被深拷贝的对象，内部含有引用类型* @Author sun* @Create 2024/5/28 20:20* @Version 1.0*/
public class DeepCloneableTarget implements Serializable, Cloneable {public static final long serialVersionUID = 1L;private String name;private int[] arr;public DeepCloneableTarget(String name, int[] arr) {this.name = name;this.arr = arr;}public int[] getArr() {return arr;}// 通过对象的序列化实现深拷贝public DeepCloneableTarget deepClone() {// 创建流对象ByteArrayOutputStream byteArrayOutputStream = null;ObjectOutputStream objectOutputStream = null;ByteArrayInputStream byteArrayInputStream = null;ObjectInputStream objectInputStream = null;try {// 序列化byteArrayOutputStream = new ByteArrayOutputStream();// 将字节数组输出流转换为对象输出流objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);// 将当前的对象以对象流的方式输出objectOutputStream.writeObject(this);// 反序列化byteArrayInputStream = new ByteArrayInputStream(byteArrayOutputStream.toByteArray());objectInputStream = new ObjectInputStream(byteArrayInputStream);DeepCloneableTarget copyObject = (DeepCloneableTarget) objectInputStream.readObject();return copyObject;} catch (Exception e) {e.printStackTrace();return null;} finally {// 关闭流try {if (byteArrayOutputStream != null) {byteArrayOutputStream.close();}if (objectOutputStream != null) {objectOutputStream.close();}if (byteArrayInputStream != null) {byteArrayInputStream.close();}if (objectInputStream != null) {objectInputStream.close();}} catch (IOException e) {e.printStackTrace();}}}
}

2.Client.java

package com.sun.deepcopy02;import java.util.Arrays;/*** Description: 原型模式的客户端* @Author sun* @Create 2024/5/28 19:43* @Version 1.0*/
public class Client {public static void main(String[] args) throws CloneNotSupportedException {DeepCloneableTarget deepCloneableTarget = new DeepCloneableTarget("sunxiansheng", new int[]{1, 2, 3});DeepCloneableTarget clone = deepCloneableTarget.deepClone();// 测试深拷贝System.out.println(deepCloneableTarget.getArr() == clone.getArr());System.out.println(Arrays.toString(deepCloneableTarget.getArr()));System.out.println(Arrays.toString(clone.getArr()));}
}

3.结果

3.原型模式的注意事项