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定义：原型模式（Prototype Pattern）是指原型实例指定创建对象的种类，并且通过拷贝这些原型创建新的对象

调用者不需要知道任何创建细节，不调用构造函数

属于创建型模式

适用场景

1.类初始化消耗资源较多

2.new产生的一个对象需要非常烦琐的过程（数据备份，访问权限等）

3.构造函数比较复杂.

4.循环体中产生大量对象时

优点

性能优良，Java自带的原型模式是基于内存二进制流的拷贝，比直接new一个对象性能上提升了许多

可以使用深克隆方式保存对象的状态，使用原型模式将对象复制一份并将其状态保存起来，简化了创建过程

缺点

必须配备克隆（或者可拷贝）方法

当对已有类进行改造的时候，需要修改代码，违反了开闭原则

深拷贝，浅拷贝需要运用得当

原型模式和单例模式是对立的

实现Cloneable的都是浅克隆

深克隆：1.序列化；2.转Json;

例子

1.自定义克隆接口

public interface IPrototype
   
     {
       T clone();}
   

public class ConcretePrototype implements IPrototype{
       private int age;    private String name;    public int getAge() {
           return age;    }    public void setAge(int age) {
           this.age = age;    }    public String getName() {
           return name;    }    public void setName(String name) {
           this.name = name;    }    @Override    public ConcretePrototype clone() {
           ConcretePrototype concretePrototype = new ConcretePrototype();        concretePrototype.setAge(this.age);        concretePrototype.setName(this.name);        return concretePrototype;    }    @Override    public String toString() {
           return "ConcretePrototype{" +                "age=" + age +                ", name='" + name + '\'' +                '}';    }}

客户端调用

public class Client {
       public static void main(String[] args) {
           ConcretePrototype prototype = new ConcretePrototype();        prototype.setAge(18);        prototype.setName("Jack");        System.out.println(prototype);        //拷贝原型对象        ConcretePrototype cloneType = prototype.clone();        System.out.println(cloneType);    }}

2.浅拷贝

public class ConcretePrototype implements Cloneable {
       private int age;    private String name;    private List
   
     hobbies;    public int getAge() {
           return age;    }    public void setAge(int age) {
           this.age = age;    }    public String getName() {
           return name;    }    public void setName(String name) {
           this.name = name;    }    public List
    
      getHobbies() {
           return hobbies;    }    public void setHobbies(List
     
       hobbies) {
           this.hobbies = hobbies;    }    @Override    public ConcretePrototype clone() {
           try {
               return (ConcretePrototype)super.clone();        } catch (CloneNotSupportedException e) {
               e.printStackTrace();        }        return null;    }    @Override    public String toString() {
           return "ConcretePrototype{" +                "age=" + age +                ", name='" + name + '\'' +                ", hobbies=" + hobbies +                '}';    }}
     
    
   

客户端调用

public class Client {
       public static void main(String[] args) {
           ConcretePrototype prototype = new ConcretePrototype();        prototype.setAge(18);        prototype.setName("Jack");        List
   
     hobbies = new ArrayList<>();        hobbies.add("打球");        hobbies.add("游戏");        prototype.setHobbies(hobbies);        System.out.println(prototype);        //拷贝原型对象        ConcretePrototype cloneType = prototype.clone();        cloneType.getHobbies().add("学习");        System.out.println("拷贝前对象：　" + prototype);        System.out.println("拷贝后对象：　" + cloneType);        System.out.println(prototype == cloneType);        System.out.println("原型对象的爱好：　" + prototype.getHobbies());        System.out.println("拷贝对象的爱好：　" + cloneType.getHobbies());        System.out.println(prototype.getHobbies() == cloneType.getHobbies());    }}
   

3.深拷贝

public class ConcretePrototype implements Cloneable ,Serializable{
       private int age;    private String name;    private List
   
     hobbies;    public int getAge() {
           return age;    }    public void setAge(int age) {
           this.age = age;    }    public String getName() {
           return name;    }    public void setName(String name) {
           this.name = name;    }    public List
    
      getHobbies() {
           return hobbies;    }    public void setHobbies(List
     
       hobbies) {
           this.hobbies = hobbies;    }    private static ConcretePrototype instance = new ConcretePrototype();    private ConcretePrototype(){
       }    public static ConcretePrototype getInstance(){
           return instance;    }    @Override    public ConcretePrototype clone() {
           try {
               return (ConcretePrototype)super.clone();        } catch (CloneNotSupportedException e) {
               e.printStackTrace();        }        return null;    }    public ConcretePrototype deepClone(){
           ConcretePrototype concretePrototype = null;        try {
               ByteArrayOutputStream bos = new ByteArrayOutputStream();            ObjectOutputStream oos = new ObjectOutputStream(bos);            oos.writeObject(this);            ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());            ObjectInputStream ois = new ObjectInputStream(bis);            concretePrototype = (ConcretePrototype)ois.readObject();            ois.close();            bis.close();            oos.close();            bos.close();        } catch (Exception e) {
               e.printStackTrace();        }        return concretePrototype;    }    public ConcretePrototype deepCloneObject(){
           ConcretePrototype concretePrototype = null;        try {
               ConcretePrototype clone = (ConcretePrototype)super.clone();            clone.hobbies = (List)((ArrayList)clone.hobbies).clone();            concretePrototype = clone;        } catch (Exception e) {
               e.printStackTrace();        }        return concretePrototype;    }    @Override    public String toString() {
           return "ConcretePrototype{" +                "age=" + age +                ", name='" + name + '\'' +                ", hobbies=" + hobbies +                '}';    }}
     
    
   

客户端调用

public class Client {
       public static void main(String[] args) {
           ConcretePrototype prototype = ConcretePrototype.getInstance();        prototype.setAge(18);        prototype.setName("Jack");        List
   
     hobbies = new ArrayList<>();        hobbies.add("打球");        hobbies.add("游戏");        prototype.setHobbies(hobbies);        System.out.println(prototype);        //拷贝原型对象        ConcretePrototype cloneType = prototype.deepCloneObject();        cloneType.getHobbies().add("学习");        System.out.println("拷贝前对象：　" + prototype);        System.out.println("拷贝后对象：　" + cloneType);        System.out.println(prototype == cloneType);        System.out.println("原型对象的爱好：　" + prototype.getHobbies());        System.out.println("拷贝对象的爱好：　" + cloneType.getHobbies());        System.out.println(prototype.getHobbies() == cloneType.getHobbies());    }}
   

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