| |
//package com.cc;
import java.util.*;
import java.lang.class;
interface book{
void saybookname();
void saybookprice();
}
class chinesebook implements book //中文书
{
private string name;
private int price;
public chinesebook(){
//this.chinesebook("chinese",10);
name = "chinesebook";
price = 10;
}
public chinesebook(string name,int price){
this.name = name;
this.price = price;
}
public void saybookname(){
system.out.println("i am a chinese book "+name);
}
public void saybookprice(){
system.out.println("my price is "+price);
}
//继承书店工厂
//
private static class factory extends bookfactory //内部类的使用
{
protected book create(){
return new chinesebook();
}
}
static { //生成1个实例后，就要把这个实例加到工厂中
system.out.println("loading chinesebook.class");
bookfactory.addfactory("chinesebook",new factory()); //为什么要把工厂
//放到list中呢？便于加载一次以后可直接调用
}
}
class englishbook implements book //英文书
{
private string name;
private int price;
public englishbook(){
//this.englishbook("english",10);
name = "englisthbook";
price = 10;
}
public englishbook(string name,int price){
this.name = name;
this.price = price;
}
public void saybookname(){
system.out.println("i am a english book "+name);
}
public void saybookprice(){
system.out.println("my price is "+price);
}
//继承书店工厂
//
private static class factory extends bookfactory
{
protected book create(){
return new englishbook();
}
}
static { //生成1个实例后，就要把这个实例加到工厂中
system.out.println("loading englishbook.class");
bookfactory.addfactory("englishbook",new factory()); //为什么要把工厂
//放到list中呢？便于加载一次以后可直接调用
}
}
abstract class bookfactory
{
protected abstract book create(); //这个方法要在具体类中实现
private static map factories = new hashmap(); //工厂map
public static void addfactory(string id,bookfactory f)
{
//加入工厂，将书和创建书的工厂加入到map中，为什么要加入创建书的工厂呢？
//因为创建书的工厂有个create（）方法，他要具体返回一个实例
system.out.println(factories.put(id,f));
}
public static final book createbook(string id){//创建书实例，书的名称作为参数，传出的是被创建好的book的实例
if (!factories.containskey(id))//当工厂中不包含这个类时要装载
{
try{
// load dynamically 动态装载
class.forname(id); //怎么加载的？只要直接执行
//这个类，类就会调用static里的语句
}catch(classnotfoundexception e){
throw new runtimeexception("error"+id);
}
// see if it was put in 看看它是否被装载
if(!factories.containskey(id))throw new runtimeexception("bad shape creation: " + id);
}
return ((bookfactory)factories.get(id)).create();
}
}
public class bookfactory2
{
string booklist[] = {"englishbook", "chinesebook","englishbook","chinesebook","chinesebook","englishbook"};
list books = new arraylist();
public void test(){
for (int i=0;i<booklist.length;i++)
{
books.add(bookfactory.createbook(booklist));
system.out.println("already create");
}
iterator it = books.iterator();
while(it.hasnext()){
book s = (book)it.next();
s.saybookname();
}
}
public static void main(string args[]) {
new bookfactory2().test();
}
}
|
|
