1 /** 
   2  * PrototypePattern Example
   3  */
   4 
   5 import java.util.*;
   6 
   7 interface Product extends Cloneable {
   8     public abstract void use(String s);
   9     public abstract Product createClone();
  10 }
  11 
  12 class Manager {
  13     private Hashtable showcase = new Hashtable();
  14     public void register(String name, Product proto) {
  15         showcase.put(name, proto);
  16     }
  17     public Product create(String protoname) {
  18         Product p = (Product)showcase.get(protoname);
  19         return p.createClone();
  20     }
  21 }
  22 
  23 class MessageBox implements Product {
  24     private char decochar;
  25     public MessageBox(char decochar) {
  26         this.decochar = decochar;
  27     }
  28     public void use(String s) {
  29         int length = s.getBytes().length;
  30         for(int i=0; i < length+4; i++) {
  31             System.out.print(decochar);
  32         }
  33         System.out.println("");
  34         System.out.println(decochar+" "+s+" "+decochar);
  35         for(int i=0; i < length+4; i++) {
  36             System.out.print(decochar);
  37         }
  38         System.out.println("");
  39     }
  40     public Product createClone() {
  41         Product p = null;
  42         try {
  43             p = (Product)clone();
  44         } catch(CloneNotSupportedException e) {
  45             e.printStackTrace();
  46         }
  47         return p;
  48     }
  49 }
  50 
  51 class UnderlinePen implements Product {
  52     private char ulchar;
  53     public UnderlinePen(char ulchar) {
  54         this.ulchar = ulchar;
  55     }
  56     public void use(String s) {
  57         int length = s.getBytes().length;
  58         System.out.println("\""+s+"\"");
  59         System.out.print(" ");
  60         for(int i=0; i < length; i++) {
  61             System.out.print(ulchar);
  62         }
  63         System.out.println("");
  64     }
  65     public Product createClone() {
  66         Product p = null;
  67         try {
  68             p = (Product)clone();
  69         } catch(CloneNotSupportedException e) {
  70             e.printStackTrace();
  71         }
  72         return p;
  73     }
  74 }
  75 
  76 public class PrototypeDisplay {
  77     public static void main(String[] args) {
  78         Manager manager = new Manager();
  79         UnderlinePen upen = new UnderlinePen('~');
  80         MessageBox mbox = new MessageBox('*');
  81         MessageBox sbox = new MessageBox('/');
  82         manager.register("strong message", upen);
  83         manager.register("warning box", mbox);
  84         manager.register("slash box", sbox);
  85 
  86         Product p1 = manager.create("strong message");
  87         p1.use("Hello, world.");
  88         Product p2 = manager.create("warning box");
  89         p2.use("Warning");
  90         Product p3 = manager.create("slash box");
  91         p3.use("Slash");
  92     }
  93 }