wmj2003的专栏

 第一种方式：拉 package com.work.pattern.observer;/** * @author wangmingjie * @date 2008-6-29下午07:21:38 */import java.util.Observable;import java.util.Observer;public class EvenObserver

工厂模式可以分为两种，一种是简单工厂，另外一种是抽象工厂。简单工厂，用来集中生成对象示例的例如，最常见的用法就是用来生成持久层对象；public class SimpleFactory {  private static UserDao  userDao = new UserDaoImpl(); public static UserDao getUserDao(){  return

  public abstract class Beverage {    String description = "Unknown Beverage";      public String getDescription() {        return description;    }    public abstract double cost(

public abstract class Duck {    FlyBehavior flyBehavior;    QuackBehavior quackBehavior;    public Duck() {    }    public void setFlyBehavior (FlyBehavior fb) {        flyBehavior

package com.work.pattern;public class Singleton2 { private static Singleton2 instance = new Singleton2(); private Singleton2(){ } public static Singleton2 getInstance(){