【Java设计模式】16-26章

行为型模式：

第16章 12模板方法模式(Template)

16.1 豆浆制作问题

16.2 模板方法模式基本介绍

16.3 模板方法模式原理类图

16.4 模板方法模式解决豆浆制作问题

package com.atguigu.template;

//抽象类，表示豆浆
public abstract class SoyaMilk {

	//模板方法, make , 模板方法可以做成final , 不让子类去覆盖.
	final void make() {
		
		select(); 
		addCondiments();
		soak();
		beat();
		
	}
	
	//选材料
	void select() {
		System.out.println("第一步：选择好的新鲜黄豆  ");
	}
	
	//添加不同的配料， 抽象方法, 子类具体实现
	abstract void addCondiments();
	
	//浸泡
	void soak() {
		System.out.println("第三步， 黄豆和配料开始浸泡， 需要3小时 ");
	}
	 
	void beat() {
		System.out.println("第四步：黄豆和配料放到豆浆机去打碎  ");
	}
}

package com.atguigu.template;

public class RedBeanSoyaMilk extends SoyaMilk {

	@Override
	void addCondiments() {
		System.out.println(" 加入上好的红豆 ");
	}

}

package com.atguigu.template;

public class PeanutSoyaMilk extends SoyaMilk {

	@Override
	void addCondiments() {
		System.out.println(" 加入上好的花生 ");
	}

}

客户端

package com.atguigu.template;

public class Client {

	public static void main(String[] args) {
		//制作红豆豆浆
		
		System.out.println("----制作红豆豆浆----");
		SoyaMilk redBeanSoyaMilk = new RedBeanSoyaMilk();
		redBeanSoyaMilk.make();
		
		System.out.println("----制作花生豆浆----");
		SoyaMilk peanutSoyaMilk = new PeanutSoyaMilk();
		peanutSoyaMilk.make();
	}

}

16.5 模板方法模式的钩子方法

package com.atguigu.template.improve;

//抽象类，表示豆浆
public abstract class SoyaMilk {

	//模板方法, make , 模板方法可以做成final , 不让子类去覆盖.
	final void make() {
		
		select(); 
		if(customerWantCondiments()) {
			addCondiments();
		}
		soak();
		beat();
		
	}
	
	//选材料
	void select() {
		System.out.println("第一步：选择好的新鲜黄豆  ");
	}
	
	//添加不同的配料， 抽象方法, 子类具体实现
	abstract void addCondiments();
	
	//浸泡
	void soak() {
		System.out.println("第三步， 黄豆和配料开始浸泡， 需要3小时 ");
	}
	 
	void beat() {
		System.out.println("第四步：黄豆和配料放到豆浆机去打碎  ");
	}
	
	//钩子方法，决定是否需要添加配料
	boolean customerWantCondiments() {
		return true;
	}
}

package com.atguigu.template.improve;

public class RedBeanSoyaMilk extends SoyaMilk {

	@Override
	void addCondiments() {
		System.out.println(" 加入上好的红豆 ");
	}

}

package com.atguigu.template.improve;

public class PeanutSoyaMilk extends SoyaMilk {

	@Override
	void addCondiments() {
		System.out.println(" 加入上好的花生 ");
	}

}

package com.atguigu.template.improve;

public class PureSoyaMilk extends SoyaMilk{

	@Override
	void addCondiments() {
		//空实现
	}
	
	@Override
	boolean customerWantCondiments() {
		return false;
	}
 
}

客户端

package com.atguigu.template.improve;

public class Client {

	public static void main(String[] args) {
		//制作红豆豆浆
		
		System.out.println("----制作红豆豆浆----");
		SoyaMilk redBeanSoyaMilk = new RedBeanSoyaMilk();
		redBeanSoyaMilk.make();
		
		System.out.println("----制作花生豆浆----");
		SoyaMilk peanutSoyaMilk = new PeanutSoyaMilk();
		peanutSoyaMilk.make();
		
		System.out.println("----制作纯豆浆----");
		SoyaMilk pureSoyaMilk = new PureSoyaMilk();
		pureSoyaMilk.make();
	}

}

16.6 模板方法模式在Spring框架应用的源码分析★

16.7 模板方法模式的注意事项和细节

第17章 13命令模式(Command)

17.1 智能生活项目需求

17.2 命令模式基本介绍

17.3 命令模式的原理类图

17.4 命令模式解决智能生活项目

package com.atguigu.command;


//创建命令接口
public interface Command {

	//执行动作(操作)
	public void execute();
	//撤销动作(操作)
	public void undo();
}

package com.atguigu.command;

public class LightReceiver {

	public void on() {
		System.out.println(" 电灯打开了.. ");
	}
	
	public void off() {
		System.out.println(" 电灯关闭了.. ");
	}
}

package com.atguigu.command;

public class LightOnCommand implements Command {

	//聚合LightReceiver
	LightReceiver light;
	
	//构造器
	public LightOnCommand(LightReceiver light) {
		super();
		this.light = light;
	}
	
	@Override
	public void execute() {
		//调用接收者的方法
		light.on();
	}

	
	@Override
	public void undo() {
		//调用接收者的方法
		light.off();
	}

}

package com.atguigu.command;

public class LightOffCommand implements Command {

	// 聚合LightReceiver
	LightReceiver light;

	// 构造器
	public LightOffCommand(LightReceiver light) {
			super();
			this.light = light;
		}

	@Override
	public void execute() {
		// 调用接收者的方法
		light.off();
	}

	@Override
	public void undo() {
		// 调用接收者的方法
		light.on();
	}
}

package com.atguigu.command;

/**
 * 没有任何命令，即空执行: 用于初始化每个按钮, 当调用空命令时，对象什么都不做
 * 其实，这样是一种设计模式, 可以省掉对空判断
 * @author Administrator
 *
 */
public class NoCommand implements Command {

	@Override
	public void execute() {

	}

	@Override
	public void undo() {

	}

}

package com.atguigu.command;

public class RemoteController {

	// 开 按钮的命令数组
	Command[] onCommands;
	Command[] offCommands;

	// 执行撤销的命令
	Command undoCommand;

	// 构造器，完成对按钮初始化

	public RemoteController() {

		onCommands = new Command[5];
		offCommands = new Command[5];

		for (int i = 0; i < 5; i++) {
			onCommands[i] = new NoCommand();
			offCommands[i] = new NoCommand();
		}
	}

	// 给我们的按钮设置你需要的命令
	public void setCommand(int no, Command onCommand, Command offCommand) {
		onCommands[no] = onCommand;
		offCommands[no] = offCommand;
	}

	// 按下开按钮
	public void onButtonWasPushed(int no) { // no 0
		// 找到你按下的开的按钮， 并调用对应方法
		onCommands[no].execute();
		// 记录这次的操作，用于撤销
		undoCommand = onCommands[no];

	}

	// 按下关按钮
	public void offButtonWasPushed(int no) { // no 0
		// 找到你按下的关的按钮， 并调用对应方法
		offCommands[no].execute();
		// 记录这次的操作，用于撤销
		undoCommand = offCommands[no];

	}
	
	// 按下撤销按钮
	public void undoButtonWasPushed() {
		undoCommand.undo();
	}

}

扩展一个TV按钮

package com.atguigu.command;

public class TVReceiver {
	
	public void on() {
		System.out.println(" 电视机打开了.. ");
	}
	
	public void off() {
		System.out.println(" 电视机关闭了.. ");
	}
}

package com.atguigu.command;

public class TVOnCommand implements Command {
	// 聚合TVReceiver
	TVReceiver tv;

	// 构造器
	public TVOnCommand(TVReceiver tv) {
		super();
		this.tv = tv;
	}

	@Override
	public void execute() {
		// 调用接收者的方法
		tv.on();
	}

	@Override
	public void undo() {
		// 调用接收者的方法
		tv.off();
	}
}

package com.atguigu.command;

public class TVOffCommand implements Command {
	// 聚合TVReceiver
	TVReceiver tv;

	// 构造器
	public TVOffCommand(TVReceiver tv) {
		super();
		this.tv = tv;
	}

	@Override
	public void execute() {
		// 调用接收者的方法
		tv.off();
	}

	@Override
	public void undo() {
		// 调用接收者的方法
		tv.on();
	}
}

客户端

package com.atguigu.command;

public class Client {

	public static void main(String[] args) {
		//使用命令设计模式，完成通过遥控器，对电灯的操作
		
		//创建电灯的对象(接受者)
		LightReceiver lightReceiver = new LightReceiver();
		
		//创建电灯相关的开关命令
		LightOnCommand lightOnCommand = new LightOnCommand(lightReceiver);
		LightOffCommand lightOffCommand = new LightOffCommand(lightReceiver);
		
		//需要一个遥控器
		RemoteController remoteController = new RemoteController();
		
		//给我们的遥控器设置命令, 比如 no = 0 是电灯的开和关的操作
		remoteController.setCommand(0, lightOnCommand, lightOffCommand);
		
		System.out.println("--------按下灯的开按钮-----------");
		remoteController.onButtonWasPushed(0);
		System.out.println("--------按下灯的关按钮-----------");
		remoteController.offButtonWasPushed(0);
		System.out.println("--------按下撤销按钮-----------");
		remoteController.undoButtonWasPushed();
		
		
		System.out.println("=========使用遥控器操作电视机==========");
		
		TVReceiver tvReceiver = new TVReceiver();
		
		TVOffCommand tvOffCommand = new TVOffCommand(tvReceiver);
		TVOnCommand tvOnCommand = new TVOnCommand(tvReceiver);
		
		//给我们的遥控器设置命令, 比如 no = 1 是电视机的开和关的操作
		remoteController.setCommand(1, tvOnCommand, tvOffCommand);
		
		System.out.println("--------按下电视机的开按钮-----------");
		remoteController.onButtonWasPushed(1);
		System.out.println("--------按下电视机的关按钮-----------");
		remoteController.offButtonWasPushed(1);
		System.out.println("--------按下撤销按钮-----------");
		remoteController.undoButtonWasPushed();

	}

}

17.5 命令模式在Spring框架JdbcTemplate应用的源码分析★

17.6 命令模式的注意事项和细节

第18章 14访问者模式(Visitor)

18.1 测评系统的需求

18.2 传统方式的问题分析

18.3 访问者模式基本介绍

18.4 访问者模式的原理类图

18.5 访问者模式应用实例

package com.atguigu.visitor;

public abstract class Action {
	
	//得到男性 的测评
	public abstract void getManResult(Man man);
	
	//得到女的 测评
	public abstract void getWomanResult(Woman woman);
}

package com.atguigu.visitor;

public abstract class Person {
	
	//提供一个方法，让访问者可以访问
	public abstract void accept(Action action);
}

package com.atguigu.visitor;

public class Man extends Person {

	@Override
	public void accept(Action action) {
		action.getManResult(this);
	}

}

package com.atguigu.visitor;

//说明
//1. 这里我们使用到了双分派, 即首先在客户端程序中，将具体状态作为参数传递Woman中(第一次分派)
//2. 然后Woman 类调用作为参数的 "具体方法" 中方法getWomanResult, 同时将自己(this)作为参数
//   传入，完成第二次的分派
public class Woman extends Person{

	@Override
	public void accept(Action action) {
		action.getWomanResult(this);
	}

}

package com.atguigu.visitor;

public class Success extends Action {

	@Override
	public void getManResult(Man man) {
		System.out.println(" 男人给的评价该歌手很成功 !");
	}

	@Override
	public void getWomanResult(Woman woman) {
		System.out.println(" 女人给的评价该歌手很成功 !");
	}

}

package com.atguigu.visitor;

public class Fail extends Action {

	@Override
	public void getManResult(Man man) {
		System.out.println(" 男人给的评价该歌手失败 !");
	}

	@Override
	public void getWomanResult(Woman woman) {
		System.out.println(" 女人给的评价该歌手失败 !");
	}

}

package com.atguigu.visitor;

public class Wait extends Action {

	@Override
	public void getManResult(Man man) {
		System.out.println(" 男人给的评价是该歌手待定 ..");
	}

	@Override
	public void getWomanResult(Woman woman) {
		System.out.println(" 女人给的评价是该歌手待定 ..");
	}

}

package com.atguigu.visitor;

import java.util.LinkedList;
import java.util.List;

//数据结构，管理很多人（Man , Woman）
public class ObjectStructure {

	//维护了一个集合
	private List<Person> persons = new LinkedList<>();
	
	//增加到list
	public void attach(Person p) {
		persons.add(p);
	}
	//移除
	public void detach(Person p) {
		persons.remove(p);
	}
	
	//显示测评情况
	public void display(Action action) {
		for(Person p: persons) {
			p.accept(action);
		}
	}
}

客户端

package com.atguigu.visitor;

public class Client {

	public static void main(String[] args) {
		//创建ObjectStructure
		ObjectStructure objectStructure = new ObjectStructure();
		
		objectStructure.attach(new Man());
		objectStructure.attach(new Woman());
		
		
		//成功
		Success success = new Success();
		objectStructure.display(success);
		
		System.out.println("===============");
		Fail fail = new Fail();
		objectStructure.display(fail);
		
		System.out.println("=======给的是待定的测评========");
		
		Wait wait = new Wait();
		objectStructure.display(wait);
	}

}

18.6 访问者模式的注意事项和细节

第19章 15迭代器模式(Iterator)

19.1 看一个具体的需求

19.2 传统的设计方案(类图)

19.3 传统的方式的问题分析

19.4 迭代器模式基本介绍

19.5 迭代器模式的原理类图

19.6 迭代器模式应用实例

package com.atguigu.iterator;

//ϵ
public class Department {

	private String name;
	private String desc;
	public Department(String name, String desc) {
		super();
		this.name = name;
		this.desc = desc;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getDesc() {
		return desc;
	}
	public void setDesc(String desc) {
		this.desc = desc;
	}
	
}

package com.atguigu.iterator;

import java.util.Iterator;


public class ComputerCollegeIterator implements Iterator {

	//这里我们需要知道Department 是以怎样的方式存放=>数组
	Department[] departments;
	int position = 0; //遍历的位置


	public ComputerCollegeIterator(Department[] departments) {
		this.departments = departments;
	}

	//判断是否还有下一个元素
	@Override
	public boolean hasNext() {
		if(position >= departments.length || departments[position] == null) {
			return false;
		}else {
			return true;
		}
	}

	@Override
	public Object next() {
		Department department = departments[position];
		position += 1;
		return department;
	}
	
	//删除的方法，默认空实现
	public void remove() {
		
	}

}

package com.atguigu.iterator;

import java.util.Iterator;
import java.util.List;

public class InfoColleageIterator implements Iterator {

	
	List<Department> departmentList; // 信息工程学院是以List方式存放系
	int index = -1;//索引
	

	public InfoColleageIterator(List<Department> departmentList) {
		this.departmentList = departmentList;
	}

	//判断list中还有没有下一个元素
	@Override
	public boolean hasNext() {
		if(index >= departmentList.size() - 1) {
			return false;
		} else {
			index += 1;
			return true;
		}
	}

	@Override
	public Object next() {
		return departmentList.get(index);
	}
	
	//空实现remove
	public void remove() {
		
	}

}

package com.atguigu.iterator;

import java.util.Iterator;

public interface College {
	
	public String getName();
	
	//增加系的方法
	public void addDepartment(String name, String desc);
	
	//返回一个迭代器,遍历
	public Iterator  createIterator();
}

package com.atguigu.iterator;

import java.util.Iterator;

public class ComputerCollege implements College {

	Department[] departments;
	int numOfDepartment = 0 ;// 保存当前数组的对象个数
	
	public ComputerCollege() {
		departments = new Department[5];
		addDepartment("Java专业", " Java专业 ");
		addDepartment("PHP专业", " PHP专业 ");
		addDepartment("大数据专业", " 大数据专业 ");
		
	}

	@Override
	public String getName() {
		return "计算机学院";
	}

	@Override
	public void addDepartment(String name, String desc) {
		Department department = new Department(name, desc);
		departments[numOfDepartment] = department;
		numOfDepartment += 1;
	}

	@Override
	public Iterator createIterator() {
		return new ComputerCollegeIterator(departments);
	}

}

package com.atguigu.iterator;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class InfoCollege implements College {

	List<Department> departmentList;
	
	
	public InfoCollege() {
		departmentList = new ArrayList<Department>();
		addDepartment("信息安全专业", " 信息安全专业 ");
		addDepartment("网络安全专业", " 网络安全专业 ");
		addDepartment("服务器安全专业", " 服务器安全专业 ");
	}
	
	@Override
	public String getName() {
		return "信息工程学院";
	}

	@Override
	public void addDepartment(String name, String desc) {
		Department department = new Department(name, desc);
		departmentList.add(department);
	}

	@Override
	public Iterator createIterator() {
		return new InfoColleageIterator(departmentList);
	}

}

package com.atguigu.iterator;

import java.util.Iterator;
import java.util.List;

public class OutPutImpl {
	
	//学院集合
	List<College> collegeList;

	public OutPutImpl(List<College> collegeList) {
		
		this.collegeList = collegeList;
	}
	//遍历所有学院,然后调用printDepartment 输出各个学院的系
	public void printCollege() {
		
		//从collegeList 取出所有学院, Java 中的 List 已经实现Iterator
		Iterator<College> iterator = collegeList.iterator();
		
		while(iterator.hasNext()) {
			//取出一个学院
			College college = iterator.next();
			System.out.println("=== "+college.getName() +"=====" );
			printDepartment(college.createIterator()); //得到对应迭代器
		}
	}

	//输出 学院输出 系
	public void printDepartment(Iterator iterator) {
		while(iterator.hasNext()) {
			Department d = (Department)iterator.next();
			System.out.println(d.getName());
		}
	}
	
}

客户端 

package com.atguigu.iterator;

import java.util.ArrayList;
import java.util.List;

public class Client {

	public static void main(String[] args) {
		//创建学院
		List<College> collegeList = new ArrayList<College>();
		
		ComputerCollege computerCollege = new ComputerCollege();
		InfoCollege infoCollege = new InfoCollege();
		
		collegeList.add(computerCollege);
		//collegeList.add(infoCollege);
		
		OutPutImpl outPutImpl = new OutPutImpl(collegeList);
		outPutImpl.printCollege();
	}

}

19.7 迭代器模式在JDK-ArrayList集合应用的源码分析★

package com.atguigu.jdk;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class IteratorDemo {

	public static void main(String[] args) {
		List<String> a = new ArrayList<>();
		a.add("jack");// ..
		// 获取到迭代器
		Iterator Itr = a.iterator();
		while (Itr.hasNext()) {
			System.out.println(Itr.next());
		}
	}
}

ArrayList内部类Itr实现Iterator接口

ArrayList内部类Itr直接使用Object[] elementData

19.8 迭代器模式的注意事项和细节

第20章 16观察者模式(Observer)★

20.1 天气预报项目需求，具体要求如下

20.2 天气预报设计方案1-普通方案

package com.atguigu.observer;

/**
 * 显示当前天气情况（可以理解成是气象站自己的网站）
 * @author Administrator
 *
 */
public class CurrentConditions {
	// 温度，气压，湿度
	private float temperature;
	private float pressure;
	private float humidity;

	//更新 天气情况，是由 WeatherData 来调用，我使用推送模式
	public void update(float temperature, float pressure, float humidity) {
		this.temperature = temperature;
		this.pressure = pressure;
		this.humidity = humidity;
		display();
	}

	//显示
	public void display() {
		System.out.println("***Today mTemperature: " + temperature + "***");
		System.out.println("***Today mPressure: " + pressure + "***");
		System.out.println("***Today mHumidity: " + humidity + "***");
	}
}

package com.atguigu.observer;

/**
 * 类是核心
 * 1. 包含最新的天气情况信息 
 * 2. 含有 CurrentConditions 对象
 * 3. 当数据有更新时，就主动的调用   CurrentConditions对象update方法(含 display), 这样他们（接入方）就看到最新的信息
 * @author Administrator
 *
 */
public class WeatherData {
	private float temperatrue;
	private float pressure;
	private float humidity;
	private CurrentConditions currentConditions;
	//加入新的第三方

	public WeatherData(CurrentConditions currentConditions) {
		this.currentConditions = currentConditions;
	}

	public float getTemperature() {
		return temperatrue;
	}

	public float getPressure() {
		return pressure;
	}

	public float getHumidity() {
		return humidity;
	}

	public void dataChange() {
		//调用 接入方的 update
		currentConditions.update(getTemperature(), getPressure(), getHumidity());
	}

	//当数据有更新时，就调用 setData
	public void setData(float temperature, float pressure, float humidity) {
		this.temperatrue = temperature;
		this.pressure = pressure;
		this.humidity = humidity;
		//调用dataChange， 将最新的信息 推送给 接入方 currentConditions
		dataChange();
	}
}

客户端

package com.atguigu.observer;

public class Client {
	public static void main(String[] args) {
		//创建接入方 currentConditions
		CurrentConditions currentConditions = new CurrentConditions();
		//创建 WeatherData 并将 接入方 currentConditions 传递到 WeatherData中
		WeatherData weatherData = new WeatherData(currentConditions);
		
		//更新天气情况
		weatherData.setData(30, 150, 40);
		
		//天气情况变化
		System.out.println("============天气情况变化=============");
		weatherData.setData(40, 160, 20);
		
	}
}

20.3 观察者模式原理

20.4 观察者模式解决天气预报需求

20.4.1 类图说明

20.4.2 代码实现

package com.atguigu.observer.improve;

//接口, 让WeatherData 来实现 
public interface Subject {
	
	public void registerObserver(Observer o);
	public void removeObserver(Observer o);
	public void notifyObservers();
}

package com.atguigu.observer.improve;

//观察者接口，有观察者来实现
public interface Observer {

	public void update(float temperature, float pressure, float humidity);
}

package com.atguigu.observer.improve;

public class CurrentConditions implements Observer {

	// 温度，气压，湿度
	private float temperature;
	private float pressure;
	private float humidity;

	// 更新 天气情况，是由 WeatherData 来调用，我使用推送模式
	public void update(float temperature, float pressure, float humidity) {
		this.temperature = temperature;
		this.pressure = pressure;
		this.humidity = humidity;
		display();
	}

	// 显示
	public void display() {
		System.out.println("***Today mTemperature: " + temperature + "***");
		System.out.println("***Today mPressure: " + pressure + "***");
		System.out.println("***Today mHumidity: " + humidity + "***");
	}
}

package com.atguigu.observer.improve;

public class BaiduSite implements Observer {

	// 温度，气压，湿度
	private float temperature;
	private float pressure;
	private float humidity;

	// 更新 天气情况，是由 WeatherData 来调用，我使用推送模式
	public void update(float temperature, float pressure, float humidity) {
		this.temperature = temperature;
		this.pressure = pressure;
		this.humidity = humidity;
		display();
	}

	// 显示
	public void display() {
		System.out.println("===百度网站====");
		System.out.println("***百度网站 气温 : " + temperature + "***");
		System.out.println("***百度网站 气压: " + pressure + "***");
		System.out.println("***百度网站 湿度: " + humidity + "***");
	}

}

package com.atguigu.observer.improve;

import java.util.ArrayList;

/**
 * 类是核心
 * 1. 包含最新的天气情况信息 
 * 2. 含有 观察者集合，使用ArrayList管理
 * 3. 当数据有更新时，就主动的调用   ArrayList, 通知所有的（接入方）就看到最新的信息
 * @author Administrator
 *
 */
public class WeatherData implements Subject {
	private float temperatrue;
	private float pressure;
	private float humidity;
	//观察者集合
	private ArrayList<Observer> observers;
	
	//加入新的第三方

	public WeatherData() {
		observers = new ArrayList<Observer>();
	}

	public float getTemperature() {
		return temperatrue;
	}

	public float getPressure() {
		return pressure;
	}

	public float getHumidity() {
		return humidity;
	}

	public void dataChange() {
		//调用 接入方的 update
		
		notifyObservers();
	}

	//当数据有更新时，就调用 setData
	public void setData(float temperature, float pressure, float humidity) {
		this.temperatrue = temperature;
		this.pressure = pressure;
		this.humidity = humidity;
		//调用dataChange， 将最新的信息 推送给 接入方 currentConditions
		dataChange();
	}

	//注册一个观察者
	@Override
	public void registerObserver(Observer o) {
		observers.add(o);
	}

	//移除一个观察者
	@Override
	public void removeObserver(Observer o) {
		if(observers.contains(o)) {
			observers.remove(o);
		}
	}

	//遍历所有的观察者，并通知
	@Override
	public void notifyObservers() {
		for(int i = 0; i < observers.size(); i++) {
			observers.get(i).update(this.temperatrue, this.pressure, this.humidity);
		}
	}
}

客户端

package com.atguigu.observer.improve;

public class Client {

	public static void main(String[] args) {
		//创建一个WeatherData
		WeatherData weatherData = new WeatherData();
		
		//创建观察者
		CurrentConditions currentConditions = new CurrentConditions();
		BaiduSite baiduSite = new BaiduSite();
		
		//注册到weatherData
		weatherData.registerObserver(currentConditions);
		weatherData.registerObserver(baiduSite);
		
		//测试
		System.out.println("通知各个注册的观察者, 看看信息");
		weatherData.setData(10f, 100f, 30.3f);
		
		
		weatherData.removeObserver(currentConditions);
		//测试
		System.out.println();
		System.out.println("通知各个注册的观察者, 看看信息");
		weatherData.setData(10f, 100f, 30.3f);
	}

}

20.4.3 观察者模式的好处

20.5 观察者模式在jdk应用的源码分析★

第21章 17中介者模式(Mediator)

21.1 智能家庭项目

21.2 传统方案解决智能家庭管理问题

21.3 传统方式的问题分析

21.4 中介者模式基本介绍

21.5 中介者模式的原理类图

21.6 中介者模式应用实例-智能家庭管理

package com.atguigu.mediator.smarthouse;

//同事抽象类
public abstract class Colleague {
	private Mediator mediator;
	public String name;

	public Colleague(Mediator mediator, String name) {

		this.mediator = mediator;
		this.name = name;

	}

	public Mediator GetMediator() {
		return this.mediator;
	}

	public abstract void SendMessage(int stateChange);
}

package com.atguigu.mediator.smarthouse;

//具体的同事类
public class Alarm extends Colleague {

	//构造器
	public Alarm(Mediator mediator, String name) {
		super(mediator, name);
		//在创建Alarm 同事对象时，将自己放入到ConcreteMediator 对象中[集合]
		mediator.Register(name, this);
	}

	public void SendAlarm(int stateChange) {
		SendMessage(stateChange);
	}

	@Override
	public void SendMessage(int stateChange) {
		//调用的中介者对象的getMessage
		this.GetMediator().GetMessage(stateChange, this.name);
	}

}

package com.atguigu.mediator.smarthouse;

public class Curtains extends Colleague {

	public Curtains(Mediator mediator, String name) {
		super(mediator, name);
		mediator.Register(name, this);
	}

	@Override
	public void SendMessage(int stateChange) {
		this.GetMediator().GetMessage(stateChange, this.name);
	}

	public void UpCurtains() {
		System.out.println("I am holding Up Curtains!");
	}

}

package com.atguigu.mediator.smarthouse;

public class CoffeeMachine extends Colleague {

	public CoffeeMachine(Mediator mediator, String name) {
		super(mediator, name);
		mediator.Register(name, this);
	}

	@Override
	public void SendMessage(int stateChange) {
		this.GetMediator().GetMessage(stateChange, this.name);
	}

	public void StartCoffee() {
		System.out.println("It's time to startcoffee!");
	}

	public void FinishCoffee() {

		System.out.println("After 5 minutes!");
		System.out.println("Coffee is ok!");
		SendMessage(0);
	}
}

package com.atguigu.mediator.smarthouse;

public class TV extends Colleague {

	public TV(Mediator mediator, String name) {
		super(mediator, name);
		mediator.Register(name, this);
	}

	@Override
	public void SendMessage(int stateChange) {
		this.GetMediator().GetMessage(stateChange, this.name);
	}

	public void StartTv() {
		System.out.println("It's time to StartTv!");
	}

	public void StopTv() {
		System.out.println("StopTv!");
	}
}

中介者 

package com.atguigu.mediator.smarthouse;

public abstract class Mediator {
	//将给中介者对象，加入到集合中
	public abstract void Register(String colleagueName, Colleague colleague);

	//接收消息, 具体的同事对象发出
	public abstract void GetMessage(int stateChange, String colleagueName);

	public abstract void SendMessage();
}

package com.atguigu.mediator.smarthouse;

import java.util.HashMap;

//具体的中介者类
public class ConcreteMediator extends Mediator {
	//集合，放入所有的同事对象
	private HashMap<String, Colleague> colleagueMap;
	private HashMap<String, String> interMap;

	public ConcreteMediator() {
		colleagueMap = new HashMap<String, Colleague>();
		interMap = new HashMap<String, String>();
	}

	@Override
	public void Register(String colleagueName, Colleague colleague) {
		colleagueMap.put(colleagueName, colleague);


		if (colleague instanceof Alarm) {
			interMap.put("Alarm", colleagueName);
		} else if (colleague instanceof CoffeeMachine) {
			interMap.put("CoffeeMachine", colleagueName);
		} else if (colleague instanceof TV) {
			interMap.put("TV", colleagueName);
		} else if (colleague instanceof Curtains) {
			interMap.put("Curtains", colleagueName);
		}

	}

	//具体中介者的核心方法
	//1. 根据得到消息，完成对应任务
	//2. 中介者在这个方法，协调各个具体的同事对象，完成任务
	@Override
	public void GetMessage(int stateChange, String colleagueName) {

		//处理闹钟发出的消息
		if (colleagueMap.get(colleagueName) instanceof Alarm) {
			if (stateChange == 0) {
				((CoffeeMachine) (colleagueMap.get(interMap
						.get("CoffeeMachine")))).StartCoffee();
				((TV) (colleagueMap.get(interMap.get("TV")))).StartTv();
			} else if (stateChange == 1) {
				((TV) (colleagueMap.get(interMap.get("TV")))).StopTv();
			}

		} else if (colleagueMap.get(colleagueName) instanceof CoffeeMachine) {
			((Curtains) (colleagueMap.get(interMap.get("Curtains"))))
					.UpCurtains();

		} else if (colleagueMap.get(colleagueName) instanceof TV) {//如果TV发现消息

		} else if (colleagueMap.get(colleagueName) instanceof Curtains) {
			//如果是以窗帘发出的消息，这里处理...
		}

	}

	@Override
	public void SendMessage() {

	}

}

客户端 

package com.atguigu.mediator.smarthouse;

public class ClientTest {

	public static void main(String[] args) {
		//创建一个中介者对象
		Mediator mediator = new ConcreteMediator();
		
		//创建Alarm 并且加入到  ConcreteMediator 对象的HashMap
		Alarm alarm = new Alarm(mediator, "alarm");
		
		//创建了CoffeeMachine 对象，并  且加入到  ConcreteMediator 对象的HashMap
		CoffeeMachine coffeeMachine = new CoffeeMachine(mediator,
				"coffeeMachine");
		
		//创建 Curtains , 并  且加入到  ConcreteMediator 对象的HashMap
		Curtains curtains = new Curtains(mediator, "curtains");
		TV tV = new TV(mediator, "TV");
		
		//让闹钟发出消息
		alarm.SendAlarm(0);
		coffeeMachine.FinishCoffee();
		alarm.SendAlarm(1);
	}

}

21.7 中介者模式的注意事项和细节

第22章 18备忘录模式(Memento)

22.1 游戏角色状态恢复问题

22.2 传统方案解决游戏角色恢复

22.3 传统方式的问题分析

22.4 备忘录模式基本介绍

22.5 备忘录模式的原理类图

package com.atguigu.memento.theory;

public class Originator {

	private String state;//状态信息

	public String getState() {
		return state;
	}

	public void setState(String state) {
		this.state = state;
	}
	
	//编写一个方法，可以保存一个状态对象 Memento
	//因此编写一个方法，返回 Memento
	public Memento saveStateMemento() {
		return new Memento(state);
	}
	
	//通过备忘录对象，恢复状态
	public void getStateFromMemento(Memento memento) {
		state = memento.getState();
	}
}

package com.atguigu.memento.theory;

public class Memento {
	private String state;

	//构造器
	public Memento(String state) {
		super();
		this.state = state;
	}

	public String getState() {
		return state;
	}
	
}

package com.atguigu.memento.theory;

import java.util.ArrayList;
import java.util.List;

public class Caretaker {
	
	//在List 集合中会有很多的备忘录对象
	private List<Memento> mementoList = new ArrayList<Memento>();
	
	public void add(Memento memento) {
		mementoList.add(memento);
	}
	
	//获取到第index个Originator 的 备忘录对象(即保存状态)
	public Memento get(int index) {
		return mementoList.get(index);
	}
}

客户端

package com.atguigu.memento.theory;

import java.util.ArrayList;
import java.util.HashMap;

public class Client {

	public static void main(String[] args) {

		Originator originator = new Originator();
		Caretaker caretaker = new Caretaker();
		
		originator.setState(" 状态#1 攻击力 100 ");
		
		//保存了当前的状态
		caretaker.add(originator.saveStateMemento());
		
		originator.setState(" 状态#2 攻击力 80 ");
		
		caretaker.add(originator.saveStateMemento());
		
		originator.setState(" 状态#3 攻击力 50 ");
		caretaker.add(originator.saveStateMemento());
		
		
		System.out.println("当前的状态是 =" + originator.getState());
		
		//希望得到状态 1, 将 originator 恢复到状态1
		
		originator.getStateFromMemento(caretaker.get(0));
		System.out.println("恢复到状态1 , 当前的状态是");
		System.out.println("当前的状态是 =" + originator.getState());
		
	}

}

22.6 游戏角色恢复状态实例

package com.atguigu.memento.game;

@Data
public class Memento {

	//攻击力
	private int vit;
	//防御力
	private int def;
	public Memento(int vit, int def) {
		super();
		this.vit = vit;
		this.def = def;
	}

}

package com.atguigu.memento.game;

import java.util.ArrayList;
import java.util.HashMap;

//守护者对象, 保存游戏角色的状态
public class Caretaker {

	//如果只保存一次状态
	private Memento  memento;
	//对GameRole 保存多次状态
	//private ArrayList<Memento> mementos;
	//对多个游戏角色保存多个状态
	//private HashMap<String, ArrayList<Memento>> rolesMementos;

	public Memento getMemento() {
		return memento;
	}

	public void setMemento(Memento memento) {
		this.memento = memento;
	}

}

package com.atguigu.memento.game;

@Data
public class GameRole {

	private int vit;
	private int def;
	
	//创建Memento ,即根据当前的状态得到Memento
	public Memento createMemento() {
		return new Memento(vit, def);
	}
	
	//从备忘录对象，恢复GameRole的状态
	public void recoverGameRoleFromMemento(Memento memento) {
		this.vit = memento.getVit();
		this.def = memento.getDef();
	}
	
	//显示当前游戏角色的状态
	public void display() {
		System.out.println("游戏角色当前的攻击力：" + this.vit + " 防御力: " + this.def);
	}
	
}

客户端 

package com.atguigu.memento.game;

public class Client {

	public static void main(String[] args) {
		//创建游戏角色
		GameRole gameRole = new GameRole();
		gameRole.setVit(100);
		gameRole.setDef(100);
		
		System.out.println("和boss大战前的状态");
		gameRole.display();
		
		//把当前状态保存caretaker
		Caretaker caretaker = new Caretaker();
		caretaker.setMemento(gameRole.createMemento());
		
		System.out.println("和boss大战~~~");
		gameRole.setDef(30);
		gameRole.setVit(30);
		
		gameRole.display();
		
		System.out.println("大战后，使用备忘录对象恢复到大战前");
		
		gameRole.recoverGameRoleFromMemento(caretaker.getMemento());
		System.out.println("恢复后的状态");
		gameRole.display();
	}

}

22.7 备忘录模式的注意事项和细节

第23章 19解释器模式(Interpreter模式)

23.1 四则运算问题

23.2 传统方案解决四则运算问题分析

23.3 解释器模式基本介绍

23.4 解释器模式的原理类图

23.5 解释器模式来实现四则

package com.atguigu.interpreter;

import java.util.HashMap;

/**
 * 抽象类表达式，通过HashMap 键值对, 可以获取到变量的值
 * 
 * @author Administrator
 *
 */
public abstract class Expression {
	// a + b - c
	// 解释公式和数值, key 就是公式(表达式) 参数[a,b,c], value就是就是具体值
	// HashMap {a=10, b=20}
	public abstract int interpreter(HashMap<String, Integer> var);
}

package com.atguigu.interpreter;

import java.util.HashMap;


/**
 * 变量的解释器
 * @author Administrator
 *
 */
public class VarExpression extends Expression {

	private String key; // key=a,key=b,key=c

	public VarExpression(String key) {
		this.key = key;
	}

	// var 就是{a=10, b=20}
	// interpreter 根据 变量名称，返回对应值
	@Override
	public int interpreter(HashMap<String, Integer> var) {
		return var.get(this.key);
	}
}

package com.atguigu.interpreter;

import java.util.HashMap;

/**
 * 抽象运算符号解析器 这里，每个运算符号，都只和自己左右两个数字有关系，
 * 但左右两个数字有可能也是一个解析的结果，无论何种类型，都是Expression类的实现类
 * 
 * @author Administrator
 *
 */
public class SymbolExpression extends Expression {

	protected Expression left;
	protected Expression right;

	public SymbolExpression(Expression left, Expression right) {
		this.left = left;
		this.right = right;
	}

	//因为 SymbolExpression 是让其子类来实现，因此 interpreter 是一个默认实现
	@Override
	public int interpreter(HashMap<String, Integer> var) {
		return 0;
	}
}

package com.atguigu.interpreter;

import java.util.HashMap;

/**
 * 加法解释器
 * @author Administrator
 *
 */
public class AddExpression extends SymbolExpression  {

	public AddExpression(Expression left, Expression right) {
		super(left, right);
	}

	//处理相加
	//var 仍然是 {a=10,b=20}..
	//一会我们debug 源码,就ok
	public int interpreter(HashMap<String, Integer> var) {
		//super.left.interpreter(var) ： 返回 left 表达式对应的值 a = 10
		//super.right.interpreter(var): 返回right 表达式对应值 b = 20
		return super.left.interpreter(var) + super.right.interpreter(var);
	}
}

package com.atguigu.interpreter;

import java.util.HashMap;

public class SubExpression extends SymbolExpression {

	public SubExpression(Expression left, Expression right) {
		super(left, right);
	}

	//求出left 和 right 表达式相减后的结果
	public int interpreter(HashMap<String, Integer> var) {
		return super.left.interpreter(var) - super.right.interpreter(var);
	}
}

package com.atguigu.interpreter;

import java.util.HashMap;
import java.util.Stack;

public class Calculator {

	// 定义表达式
	private Expression expression;

	// 构造函数传参，并解析
	public Calculator(String expStr) { // expStr = a+b
		// 安排运算先后顺序
		Stack<Expression> stack = new Stack<>();
		// 表达式拆分成字符数组 
		char[] charArray = expStr.toCharArray();// [a, +, b]

		Expression left = null;
		Expression right = null;
		//遍历我们的字符数组， 即遍历  [a, +, b]
		//针对不同的情况，做处理
		for (int i = 0; i < charArray.length; i++) {
			switch (charArray[i]) {
			case '+': //
				left = stack.pop();// 从stack取出left => "a"
				right = new VarExpression(String.valueOf(charArray[++i]));// 取出右表达式 "b"
				stack.push(new AddExpression(left, right));// 然后根据得到left 和 right 构建 AddExpresson加入stack
				break;
			case '-': // 
				left = stack.pop();
				right = new VarExpression(String.valueOf(charArray[++i]));
				stack.push(new SubExpression(left, right));
				break;
			default: 
				//如果是一个 Var 就创建要给 VarExpression 对象，并push到 stack
				stack.push(new VarExpression(String.valueOf(charArray[i])));
				break;
			}
		}
		//当遍历完整个 charArray 数组后，stack 就得到最后Expression
		this.expression = stack.pop();
	}

	public int run(HashMap<String, Integer> var) {
		//最后将表达式a+b和 var = {a=10,b=20}
		//然后传递给expression的interpreter进行解释执行
		return this.expression.interpreter(var);
	}
}

客户端

package com.atguigu.interpreter;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashMap;

public class ClientTest {

	public static void main(String[] args) throws IOException {
		String expStr = getExpStr(); // a+b
		HashMap<String, Integer> var = getValue(expStr);// var {a=10, b=20}
		Calculator calculator = new Calculator(expStr);
		System.out.println("运算结果：" + expStr + "=" + calculator.run(var));
	}

	// 获得表达式
	public static String getExpStr() throws IOException {
		System.out.print("请输入表达式：");
		return (new BufferedReader(new InputStreamReader(System.in))).readLine();
	}

	// 获得值映射
	public static HashMap<String, Integer> getValue(String expStr) throws IOException {
		HashMap<String, Integer> map = new HashMap<>();

		for (char ch : expStr.toCharArray()) {
			if (ch != '+' && ch != '-') {
				if (!map.containsKey(String.valueOf(ch))) {
					System.out.print("请输入" + String.valueOf(ch) + "的值：");
					String in = (new BufferedReader(new InputStreamReader(System.in))).readLine();
					map.put(String.valueOf(ch), Integer.valueOf(in));
				}
			}
		}

		return map;
	}
}

23.6 解释器模式在Spring框架应用的源码分析★

package com.atguigu.spring.test;

import org.springframework.expression.Expression;
import org.springframework.expression.spel.standard.SpelExpressionParser;

public class Interpreter {

	public static void main(String[] args) {
		//创建一个 Parser 对象
		SpelExpressionParser parser = new SpelExpressionParser();
		//
		//通过 Parser 对象 获取到一个Expression对象
		//会根据不同的  Parser 对象 ，返回不同的 Expression对象
		Expression expression = parser.parseExpression("10 * (2 + 1) * 1 + 66"); //96
		int result = (Integer) expression.getValue();
		System.out.println(result);

	}

}

23.7 解释器模式的注意事项和细节

第24章 20状态模式(State)

24.1 APP抽奖活动问题

24.2 状态模式基本介绍

24.3 状态模式的原理类图

24.4 状态模式解决APP抽奖问题

package com.atguigu.state;

/**
 * 状态抽象类
 * @author Administrator
 *
 */
public abstract class State {

	// 扣除积分 - 50
    public abstract void deductMoney();

    // 是否抽中奖品
    public abstract boolean raffle();

    // 发放奖品
    public abstract  void dispensePrize();

}

package com.atguigu.state;

/**
 * 不能抽奖状态
 * @author Administrator
 *
 */
public class NoRaffleState extends State {

	 // 初始化时传入活动引用，扣除积分后改变其状态
    RaffleActivity activity;

    public NoRaffleState(RaffleActivity activity) {
        this.activity = activity;
    }

    // 当前状态可以扣积分 , 扣除后，将状态设置成可以抽奖状态
    @Override
    public void deductMoney() {
        System.out.println("扣除50积分成功，您可以抽奖了");
        activity.setState(activity.getCanRaffleState());
    }

    // 当前状态不能抽奖
    @Override
    public boolean raffle() {
        System.out.println("扣了积分才能抽奖喔！");
        return false;
    }

    // 当前状态不能发奖品
    @Override
    public void dispensePrize() {
        System.out.println("不能发放奖品");
    }
}

package com.atguigu.state;

import java.util.Random;

/**
 * 可以抽奖的状态
 * @author Administrator
 *
 */
public class CanRaffleState extends State {

    RaffleActivity activity;

    public CanRaffleState(RaffleActivity activity) {
        this.activity = activity;
    }

    //已经扣除了积分，不能再扣
    @Override
    public void deductMoney() {
        System.out.println("已经扣取过了积分");
    }

    //可以抽奖, 抽完奖后，根据实际情况，改成新的状态
    @Override
    public boolean raffle() {
        System.out.println("正在抽奖，请稍等！");
        Random r = new Random();
        int num = r.nextInt(10);
        // 10%中奖机会
        if(num == 0){
            // 改变活动状态为发放奖品 context
            activity.setState(activity.getDispenseState());
            return true;
        }else{
            System.out.println("很遗憾没有抽中奖品！");
            // 改变状态为不能抽奖
            activity.setState(activity.getNoRafflleState());
            return false;
        }
    }

    // 不能发放奖品
    @Override
    public void dispensePrize() {
        System.out.println("没中奖，不能发放奖品");
    }
}

package com.atguigu.state;

/**
 * 发放奖品的状态
 * @author Administrator
 *
 */
public class DispenseState extends State {

	 // 初始化时传入活动引用，发放奖品后改变其状态
    RaffleActivity activity;

    public DispenseState(RaffleActivity activity) {
        this.activity = activity;
    }
    
    //

    @Override
    public void deductMoney() {
        System.out.println("不能扣除积分");
    }

    @Override
    public boolean raffle() {
        System.out.println("不能抽奖");
        return false;
    }

    //发放奖品
    @Override
    public void dispensePrize() {
        if(activity.getCount() > 0){
            System.out.println("恭喜中奖了");
            // 改变状态为不能抽奖
            activity.setState(activity.getNoRafflleState());
        }else{
            System.out.println("很遗憾，奖品发送完了");
            // 改变状态为奖品发送完毕, 后面我们就不可以抽奖
            activity.setState(activity.getDispensOutState());
            //System.out.println("抽奖活动结束");
            //System.exit(0);
        }

    }
}

package com.atguigu.state;

/**
 * 奖品发放完毕状态
 * 说明，当我们activity 改变成 DispenseOutState， 抽奖活动结束
 * @author Administrator
 *
 */
public class DispenseOutState extends State {

	// 初始化时传入活动引用
    RaffleActivity activity;

    public DispenseOutState(RaffleActivity activity) {
        this.activity = activity;
    }
    @Override
    public void deductMoney() {
        System.out.println("奖品发送完了，请下次再参加");
    }

    @Override
    public boolean raffle() {
        System.out.println("奖品发送完了，请下次再参加");
        return false;
    }

    @Override
    public void dispensePrize() {
        System.out.println("奖品发送完了，请下次再参加");
    }
}

活动

package com.atguigu.state;

/**
 * 抽奖活动 //
 * 
 * @author Administrator
 *
 */
public class RaffleActivity {

	// state 表示活动当前的状态，是变化的
    State state = null;
    // 奖品数量
    int count = 0;
    
    // 四个属性，表示四种状态
    State noRafflleState = new NoRaffleState(this);
    State canRaffleState = new CanRaffleState(this);
    
    State dispenseState =   new DispenseState(this);
    State dispensOutState = new DispenseOutState(this);

    //构造器
    //1. 初始化当前的状态为 noRafflleState（即不能抽奖的状态）
    //2. 初始化奖品的数量 
    public RaffleActivity( int count) {
        this.state = getNoRafflleState();
        this.count = count;
    }

    //扣分, 调用当前状态的 deductMoney
    public void debuctMoney(){
        state.deductMoney();
    }

    //抽奖 
    public void raffle(){
    	// 如果当前的状态是抽奖成功
        if(state.raffle()){
        	//领取奖品
            state.dispensePrize();
        }

    }

    public State getState() {
        return state;
    }

    public void setState(State state) {
        this.state = state;
    }

    //这里请大家注意，每领取一次奖品，count--
    public int getCount() {
    	int curCount = count; 
    	count--;
        return curCount;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public State getNoRafflleState() {
        return noRafflleState;
    }

    public void setNoRafflleState(State noRafflleState) {
        this.noRafflleState = noRafflleState;
    }

    public State getCanRaffleState() {
        return canRaffleState;
    }

    public void setCanRaffleState(State canRaffleState) {
        this.canRaffleState = canRaffleState;
    }

    public State getDispenseState() {
        return dispenseState;
    }

    public void setDispenseState(State dispenseState) {
        this.dispenseState = dispenseState;
    }

    public State getDispensOutState() {
        return dispensOutState;
    }

    public void setDispensOutState(State dispensOutState) {
        this.dispensOutState = dispensOutState;
    }
}

客户端

package com.atguigu.state;

/**
 * 状态模式测试类
 * @author Administrator
 *
 */
public class ClientTest {

	public static void main(String[] args) {
		// 创建活动对象，奖品有1个奖品
        RaffleActivity activity = new RaffleActivity(1);

        // 我们连续抽300次奖
        for (int i = 0; i < 30; i++) {
            System.out.println("--------第" + (i + 1) + "次抽奖----------");
            // 参加抽奖，第一步点击扣除积分
            activity.debuctMoney();

            // 第二步抽奖
            activity.raffle();
        }
	}

}

24.5 状态模式在实际项目-借贷平台 源码剖析★

package com.atguigu.state.money;

/**
 * 状态接口
 * @author Administrator
 *
 */
public interface State {

	/**
     * 电审
     */
    void checkEvent(Context context);

    /**
     * 电审失败
     */
    void checkFailEvent(Context context);

    /**
     * 定价发布
     */
    void makePriceEvent(Context context);

    /**
     * 接单
     */
    void acceptOrderEvent(Context context);

    /**
     * 无人接单失效
     */
    void notPeopleAcceptEvent(Context context);

    /**
     * 付款
     */
    void payOrderEvent(Context context);

    /**
     * 接单有人支付失效
     */
    void orderFailureEvent(Context context);

    /**
     * 反馈
     */
    void feedBackEvent(Context context);


    String getCurrentState();
}

package com.atguigu.state.money;

public abstract class AbstractState implements State {

	protected static final RuntimeException EXCEPTION = new RuntimeException("操作流程不允许");

	//抽象类，默认实现了 State 接口的所有方法
	//该类的所有方法，其子类(具体的状态类)，可以有选择的进行重写
	
    @Override
    public void checkEvent(Context context) {
        throw EXCEPTION;
    }

    @Override
    public void checkFailEvent(Context context) {
        throw EXCEPTION;
    }

    @Override
    public void makePriceEvent(Context context) {
        throw EXCEPTION;
    }

    @Override
    public void acceptOrderEvent(Context context) {
        throw EXCEPTION;
    }

    @Override
    public void notPeopleAcceptEvent(Context context) {
        throw EXCEPTION;
    }

    @Override
    public void payOrderEvent(Context context) {
        throw EXCEPTION;
    }

    @Override
    public void orderFailureEvent(Context context) {
        throw EXCEPTION;
    }

    @Override
    public void feedBackEvent(Context context) {
        throw EXCEPTION;
    }
}

AllState 

package com.atguigu.state.money;

//各种具体状态类
class FeedBackState extends AbstractState {

	@Override
	public String getCurrentState() {
		return StateEnum.FEED_BACKED.getValue();
	}
}

class GenerateState extends AbstractState {

	@Override
	public void checkEvent(Context context) {
		context.setState(new ReviewState());
	}

	@Override
	public void checkFailEvent(Context context) {
		context.setState(new FeedBackState());
	}

	@Override
	public String getCurrentState() {
		return StateEnum.GENERATE.getValue();
	}
}

class NotPayState extends AbstractState {

	@Override
	public void payOrderEvent(Context context) {
		context.setState(new PaidState());
	}

	@Override
	public void feedBackEvent(Context context) {
		context.setState(new FeedBackState());
	}

	@Override
	public String getCurrentState() {
		return StateEnum.NOT_PAY.getValue();
	}
}

class PaidState extends AbstractState {

	@Override
	public void feedBackEvent(Context context) {
		context.setState(new FeedBackState());
	}

	@Override
	public String getCurrentState() {
		return StateEnum.PAID.getValue();
	}
}

class PublishState extends AbstractState {

	@Override
	public void acceptOrderEvent(Context context) {
		//把当前状态设置为  NotPayState。。。
		//至于应该变成哪个状态，由流程图来决定
		context.setState(new NotPayState());
	}

	@Override
	public void notPeopleAcceptEvent(Context context) {
		context.setState(new FeedBackState());
	}

	@Override
	public String getCurrentState() {
		return StateEnum.PUBLISHED.getValue();
	}
}

class ReviewState extends AbstractState {

	@Override
	public void makePriceEvent(Context context) {
		context.setState(new PublishState());
	}

	@Override
	public String getCurrentState() {
		return StateEnum.REVIEWED.getValue();
	}

}

package com.atguigu.state.money;

/**
 * 状态枚举类
 * @author Administrator
 *
 */
public enum StateEnum {

	 //订单生成
    GENERATE(1, "GENERATE"),

    //已审核
    REVIEWED(2, "REVIEWED"),

    //已发布
    PUBLISHED(3, "PUBLISHED"),

    //待付款
    NOT_PAY(4, "NOT_PAY"),

    //已付款
    PAID(5, "PAID"),

    //已完结
    FEED_BACKED(6, "FEED_BACKED");

    private int key;
    private String value;

    StateEnum(int key, String value) {
        this.key = key;
        this.value = value;
    }
    public int getKey() {return key;}
    public String getValue() {return value;}
}

package com.atguigu.state.money;

//环境上下文
public class Context extends AbstractState{
	//当前的状态 state, 根据我们的业务流程处理，不停的变化
	private State state;

    @Override
    public void checkEvent(Context context) {
        state.checkEvent(this);
        getCurrentState();
    }

    @Override
    public void checkFailEvent(Context context) {
        state.checkFailEvent(this);
        getCurrentState();
    }

    @Override
    public void makePriceEvent(Context context) {
        state.makePriceEvent(this);
        getCurrentState();
    }

    @Override
    public void acceptOrderEvent(Context context) {
        state.acceptOrderEvent(this);
        getCurrentState();
    }

    @Override
    public void notPeopleAcceptEvent(Context context) {
        state.notPeopleAcceptEvent(this);
        getCurrentState();
    }

    @Override
    public void payOrderEvent(Context context) {
        state.payOrderEvent(this);
        getCurrentState();
    }

    @Override
    public void orderFailureEvent(Context context) {
        state.orderFailureEvent(this);
        getCurrentState();
    }

    @Override
    public void feedBackEvent(Context context) {
        state.feedBackEvent(this);
        getCurrentState();
    }

    public State getState() {
        return state;
    }

    public void setState(State state) {
        this.state = state;
    }

    @Override
    public String getCurrentState() {
        System.out.println("当前状态 : " + state.getCurrentState());
        return state.getCurrentState();
    }
}

客户端

package com.atguigu.state.money;

/**测试类*/
public class ClientTest {

	public static void main(String[] args) {
		//创建context 对象
		Context context = new Context();
        //将当前状态设置为 PublishState
		context.setState(new PublishState());
        System.out.println(context.getCurrentState());
        
//        //publish --> not pay
        context.acceptOrderEvent(context);
//        //not pay --> paid
        context.payOrderEvent(context);
//        // 失败, 检测失败时，会抛出异常
//        try {
//        	context.checkFailEvent(context);
//        	System.out.println("流程正常..");
//		} catch (Exception e) {
//			// TODO: handle exception
//			System.out.println(e.getMessage());
//		}
        
	}

}

24.6 状态模式的注意事项和细节

第25章 21策略模式(Strategy)

25.1 鸭子问题

25.2 传统方案解决鸭子问题

package com.atguigu.strategy;

public abstract class Duck {

	public Duck() {
	
	}

	public abstract void display();//显示鸭子信息
	
	public void quack() {
		System.out.println("鸭子嘎嘎叫~~");
	}
	
	public void swim() {
		System.out.println("鸭子会游泳~~");
	}
	
	public void fly() {
		System.out.println("鸭子会飞翔~~~");
	}
	
}

package com.atguigu.strategy;

public class WildDuck extends Duck {

	@Override
	public void display() {
		System.out.println(" 这是野鸭 ");
	}

}

package com.atguigu.strategy;

public class PekingDuck extends Duck {

	@Override
	public void display() {
		System.out.println("~~北京鸭~~~");
	}
	
	//因为北京鸭不能飞翔，因此需要重写fly
	@Override
	public void fly() {
		System.out.println("北京鸭不能飞翔");
	}

}

package com.atguigu.strategy;

public class ToyDuck extends Duck{

	@Override
	public void display() {
		System.out.println("玩具鸭");
	}

	//需要重写父类的所有方法
	
	public void quack() {
		System.out.println("玩具鸭不能叫~~");
	}
	
	public void swim() {
		System.out.println("玩具鸭不会游泳~~");
	}
	
	public void fly() {
		System.out.println("玩具鸭不会飞翔~~~");
	}
}

25.3 传统方式解决鸭子问题分析和解决方案

25.4 策略模式基本介绍

25.5 策略模式的原理类图

25.6 策略模式解决鸭子问题

package com.atguigu.strategy.improve;

public abstract class Duck {

	//属性, 策略接口
	FlyBehavior flyBehavior;
	//其它属性<->策略接口
	QuackBehavior quackBehavior;
	
	public Duck() {
	
	}

	public abstract void display();//显示鸭子信息
	
	public void quack() {
		System.out.println("鸭子嘎嘎叫~~");
	}
	
	public void swim() {
		System.out.println("鸭子会游泳~~");
	}
	
	public void fly() {
		
		//改进
		if(flyBehavior != null) {
			flyBehavior.fly();
		}
	}

	public void setFlyBehavior(FlyBehavior flyBehavior) {
		this.flyBehavior = flyBehavior;
	}

	public void setQuackBehavior(QuackBehavior quackBehavior) {
		this.quackBehavior = quackBehavior;
	}
	
}

飞行策略

package com.atguigu.strategy.improve;

public interface FlyBehavior {
	
	void fly(); // 子类具体实现
}

package com.atguigu.strategy.improve;

public class GoodFlyBehavior implements FlyBehavior {

	@Override
	public void fly() {
		System.out.println(" 飞翔技术高超 ~~~");
	}

}

package com.atguigu.strategy.improve;

public class BadFlyBehavior implements FlyBehavior {

	@Override
	public void fly() {
		System.out.println(" 飞翔技术一般 ");
	}

}

package com.atguigu.strategy.improve;

public class NoFlyBehavior implements FlyBehavior{

	@Override
	public void fly() {
		System.out.println(" 不会飞翔  ");
	}

}

鸭子种类

package com.atguigu.strategy.improve;

public class WildDuck extends Duck {

	
	//构造器，传入FlyBehavor 的对象
	public  WildDuck() {
		flyBehavior = new GoodFlyBehavior();
	}
	
	
	@Override
	public void display() {
		System.out.println(" 这是野鸭 ");
	}

}

package com.atguigu.strategy.improve;

public class PekingDuck extends Duck {

	
	//假如北京鸭可以飞翔，但是飞翔技术一般
	public PekingDuck() {
		flyBehavior = new BadFlyBehavior();
		
	}
	
	@Override
	public void display() {
		System.out.println("~~北京鸭~~~");
	}

}

package com.atguigu.strategy.improve;

public class ToyDuck extends Duck{

	public ToyDuck() {
		flyBehavior = new NoFlyBehavior();
	}
	
	@Override
	public void display() {
		System.out.println("玩具鸭");
	}

	//需要重写父类的所有方法
	
	public void quack() {
		System.out.println("玩具鸭不能叫~~");
	}
	
	public void swim() {
		System.out.println("玩具鸭不会游泳~~");
	}
	
}

客户端 

package com.atguigu.strategy.improve;

public class Client {

	public static void main(String[] args) {
		WildDuck wildDuck = new WildDuck();
		wildDuck.fly();//
		
		ToyDuck toyDuck = new ToyDuck();
		toyDuck.fly();
		
		PekingDuck pekingDuck = new PekingDuck();
		pekingDuck.fly();
		
		//动态改变某个对象的行为, 北京鸭 不能飞
		pekingDuck.setFlyBehavior(new NoFlyBehavior());
		System.out.println("北京鸭的实际飞翔能力");
		pekingDuck.fly();
	}

}

叫声策略

package com.atguigu.strategy.improve;

public interface QuackBehavior {
	void quack();//子类实现
}

25.7 策略模式在JDK-Arrays应用的源码分析★

package com.atguigu.jdk;

import java.util.Arrays;
import java.util.Comparator;


public class Strategy {

	public static void main(String[] args) {
		//数组
		Integer[] data = { 9, 1, 2, 8, 4, 3 };
		// 实现升序排序，返回-1放左边，1放右边，0保持不变
		
		// 说明
		// 1. 实现了Comparator 接口（策略接口），匿名类 对象 new Comparator<Integer<(){..}
		// 2. 对象 new Comparator<Integer>(){..} 就是实现了策略接口 的对象
		// 3. public int compare(Integer o1, Integer o2){} ָ指定具体的处理方式
		Comparator<Integer> comparator = new Comparator<Integer>() {
			public int compare(Integer o1, Integer o2) {
				if (o1 > o2) {
					return -1;
				} else {
					return 1;
				}
			};
		};
		
		// 说明
		/*
		 * public static <T> void sort(T[] a, Comparator<? super T> c) {
		        if (c == null) {
		            sort(a); //默认方法
		        } else { 
		            if (LegacyMergeSort.userRequested)
		                legacyMergeSort(a, c); //使用策略对象c
		            else
		            	// 使用策略对象c
		                TimSort.sort(a, 0, a.length, c, null, 0, 0);
		        }
		    }
		 */
		//方式1
		Arrays.sort(data, comparator);
		
		System.out.println(Arrays.toString(data)); // 降序排序

		
		//方式2- 通过lambda 表达式实现 策略模式
		Integer[] data2 = { 19, 11, 12, 18, 14, 13 };
		
		Arrays.sort(data2, (var1, var2) -> {
			if(var1.compareTo(var2) > 0) {
				return -1;
			} else {
				return 1;
			}
		});
		
		System.out.println("data2=" + Arrays.toString(data2));
		
	}

}

25.8 策略模式的注意事项和细节

第26章 22职责链模式(责任链模式,Chain of Responsibility)

26.1 OA系统采购审批需求

26.2 传统方案解决OA系统审批

26.3 传统方案解决OA系统审批问题分析

26.4 职责链模式基本介绍

26.5 职责链模式的原理类图

26.6 职责链模式解决OA系统采购审批

package com.atguigu.responsibilitychain;

//请求类
public class PurchaseRequest {

	private int type = 0; //请求类型
	private float price = 0.0f; //请求金额
	private int id = 0;
	//构造器
	public PurchaseRequest(int type, float price, int id) {
		this.type = type;
		this.price = price;
		this.id = id;
	}
	public int getType() {
		return type;
	}
	public float getPrice() {
		return price;
	}
	public int getId() {
		return id;
	}
	
	
}

package com.atguigu.responsibilitychain;

public abstract class Approver {

	Approver approver;  //下一个处理者
	String name; // 名字
	
	public Approver(String name) {
		this.name = name;
	}

	//下一个处理者
	public void setApprover(Approver approver) {
		this.approver = approver;
	}
	
	//处理审批请求的方法，得到一个请求, 处理是子类完成，因此该方法做成抽象
	public abstract void processRequest(PurchaseRequest purchaseRequest);
	
}

package com.atguigu.responsibilitychain;

public class DepartmentApprover extends Approver {

	public DepartmentApprover(String name) {
		super(name);
	}
	
	@Override
	public void processRequest(PurchaseRequest purchaseRequest) {
		if(purchaseRequest.getPrice() <= 5000) {
			System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
		}else {
			approver.processRequest(purchaseRequest);
		}
	}

}

package com.atguigu.responsibilitychain;

public class CollegeApprover extends Approver {

	public CollegeApprover(String name) {
		super(name);
	}
	
	@Override
	public void processRequest(PurchaseRequest purchaseRequest) {
		if(purchaseRequest.getPrice() > 5000 && purchaseRequest.getPrice() <= 10000) {
			System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
		}else {
			approver.processRequest(purchaseRequest);
		}
	}
}

package com.atguigu.responsibilitychain;

public class ViceSchoolMasterApprover extends Approver {

	public ViceSchoolMasterApprover(String name) {
		super(name);
	}
	
	@Override
	public void processRequest(PurchaseRequest purchaseRequest) {
		if(purchaseRequest.getPrice() > 10000 && purchaseRequest.getPrice() <= 30000) {
			System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
		}else {
			approver.processRequest(purchaseRequest);
		}
	}
}

package com.atguigu.responsibilitychain;

public class SchoolMasterApprover extends Approver {

	public SchoolMasterApprover(String name) {
		super(name);
	}
	
	@Override
	public void processRequest(PurchaseRequest purchaseRequest) {
		if(purchaseRequest.getPrice() > 30000) {
			System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
		}else {
			approver.processRequest(purchaseRequest);
		}
	}
}

客户端

package com.atguigu.responsibilitychain;

public class Client {

	public static void main(String[] args) {
		//创建一个请求
		PurchaseRequest purchaseRequest = new PurchaseRequest(1, 31000, 1);
		
		//创建相关的审批人
		DepartmentApprover departmentApprover = new DepartmentApprover("张主任");
		CollegeApprover collegeApprover = new CollegeApprover("李院长");
		ViceSchoolMasterApprover viceSchoolMasterApprover = new ViceSchoolMasterApprover("王副校");
		SchoolMasterApprover schoolMasterApprover = new SchoolMasterApprover("佟校长");
	
	
		//需要将各个审批级别的下一个设置好 (处理人构成环形: )
		departmentApprover.setApprover(collegeApprover);
		collegeApprover.setApprover(viceSchoolMasterApprover);
		viceSchoolMasterApprover.setApprover(schoolMasterApprover);
		schoolMasterApprover.setApprover(departmentApprover);
		

		departmentApprover.processRequest(purchaseRequest);
		viceSchoolMasterApprover.processRequest(purchaseRequest);
	}

}

26.7 职责链模式在SpringMVC框架应用的源码分析★

preHandle 

postHandle 

afterCompletion 

package com.atguigu.spring.test;

import org.springframework.web.servlet.HandlerExecutionChain;
import org.springframework.web.servlet.HandlerInterceptor;

public class ResponsibilityChain {

	public static void main(String[] args) {

		// DispatcherServlet 
		
		//说明
		/*
		 * 
		 *  protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
		 *   HandlerExecutionChain mappedHandler = null; 
		 *   mappedHandler = getHandler(processedRequest);//获取到HandlerExecutionChain对象
		 *    //在 mappedHandler.applyPreHandle 内部 得到啦 HandlerInterceptor interceptor
		 *    //调用了拦截器的  interceptor.preHandle
		 *   if (!mappedHandler.applyPreHandle(processedRequest, response)) {
					return;
				}
				
			  //说明：mappedHandler.applyPostHandle 方法内部获取到拦截器，并调用 
			  //拦截器的  interceptor.postHandle(request, response, this.handler, mv);
			 mappedHandler.applyPostHandle(processedRequest, response, mv);
		 *  }
		 *  
		 *  
		 *  //说明：在  mappedHandler.applyPreHandle内部中，
		 *  还调用了  triggerAfterCompletion 方法，该方法中调用了  
		 *  HandlerInterceptor interceptor = getInterceptors()[i];
			try {
				interceptor.afterCompletion(request, response, this.handler, ex);
			}
			catch (Throwable ex2) {
				logger.error("HandlerInterceptor.afterCompletion threw exception", ex2);
			}
		 */
	
	}

}

26.8 职责链模式的注意事项和细节

设计模式在框架或项目中源码分析的说明