Prototype模式

Prototype模式

• Prototype(原型)

  负责定义用于复制现有实例来生成新实例的方法。

• ConcretePrototype(具体的原型)

  ConcreteProtype角色负责实现复制现有实例并生成新实例的方法。在实例程序中，由MessageBox类和UnderlinePen类扮演此角色。

• Client(使用者)

  类和接口的一览表

  包	名字	说明
  framework	Product	声明了抽象方法use和createClone的接口
  framework	Manager	调用createClone方法复制实例的类
  无名	MessageBox	将字符串放入方框中并使其显示出来的类。实现了user方法和createClone方法
  无名	UnderlinePen	给字符串加上下划线并使其显示出来的类。实现了user方法和createClone方法
  无名	Main	运行程序

  

Main.java

import framework.Manager;
import framework.Product;

public class Main {
    public static void main(String[] args) {
        Manager manager = new Manager();
        UnderlinePen upen = new UnderlinePen("~");
        UnderlinePen upen2 = new UnderlinePen("*");
        manager.register("strong message",upen);
        manager.register("waring box",upen2);
        Product p1 = manager.create("strong message");
        Product p2 = manager.create("waring box");
        p1.use("Hello,world");
        p2.use("waring box");
    }
}

Framework

Manager.java

package framework;

import java.util.HashMap;

public class Manager {
    private HashMap showcase = new HashMap<>();
    public void register(String name,Product proto){
        showcase.put(name,proto);
    }

    public Product create(String protoname){
        Product p = (Product)showcase.get(protoname);
        return p.createClone();

    }
}

Product.java

package framework;

public interface Product extends Cloneable{
    public abstract void use(String s);
    public abstract Product createClone();
}

MessageBox.java

import framework.Product;

public class MessageBox implements Product {

    private char decochar;

    public MessageBox(char decochar) {
        this.decochar = decochar;
    }


    @Override
    public void use(String s) {
        int length = s.length();
        for (int i = 0; i < length ; i++) {
            System.out.println(decochar);
        }

        System.out.println("");
        System.out.println(decochar+" "+s+" "+decochar );
        for (int i = 0; i < length + 4; i++) {
            System.out.print(decochar);
        }
        System.out.println("");
    }


    @Override
    public Product createClone() {
        Product p = null;

        try {
            p = (Product)clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return p;


    }
}

import framework.Product;

public class UnderlinePen implements Product {
    String ulchar;

    public UnderlinePen(String ulchar) {
        this.ulchar = ulchar;
    }

    @Override
    public void use(String s) {
        int length = s.length();
        System.out.println("\""+s+"\"");
        System.out.print(" ");
        for (int i = 0; i < length; i++) {
            System.out.print(ulchar);
        }
        System.out.println("");

    }

    @Override
    public Product createClone() {
        Product p = null;

        try {
            p = (Product)clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return p;

    }
}