六、Prototype 原型设计模式

需求：使用 new 生成实例需要指定类名，在不指定类的情况下生成实例

代码清单：

原型接口 Product：

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

实现 UnderlinePen：

public class UnderlinePen implements Product{

    private char ulchar;

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

    @Override
    public void use(String s) {
        int length = s.getBytes().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 creatClone() {
        Product p = null;
        try{
            p=(Product)clone();
        }catch (CloneNotSupportedException e){
            e.printStackTrace();
        }
        return p;
    }
}

实现：MessageBox

public class MessageBox implements Product{

    private char decochar;

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

    @Override
    public void use(String s) {
        int length = s.getBytes().length;
        for(int i=0;i<length+4;i++){
            System.out.print(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 creatClone() {
        Product p = null;
        try{
            p = (Product)clone();
        }catch (CloneNotSupportedException e){
            e.printStackTrace();
        }
        return p;
    }
}

Manager 管理类：

public class Manager {

    private HashMap showcase = new HashMap();

    public void register(String name, Product product){
        showcase.put(name,product);
    }

    public Product create(String productName){
        Product p = (Product)showcase.get(productName);
        return p.creatClone();
    }
}

测试类：

public class Main {
    public static void main(String[] args){

        Manager manager = new Manager();
        UnderlinePen underlinePen = new UnderlinePen(‘.‘);
        MessageBox messageBox = new MessageBox(‘*‘);
        MessageBox messageBox1 = new MessageBox(‘/‘);

        manager.register("Strong",underlinePen);
        manager.register("Warn",messageBox);
        manager.register("Flash",messageBox1);

        Product p1 = manager.create("Strong");
        p1.use("Hello,world");

        Product p2 = manager.create("Warn");
        p2.use("Hello,World");

        Product p3 = manager.create("Flash");
        p3.use("Hello,world");
    }
}

结果：