设计模式之《模板方法模式》

模板方法模式（Template Method Pattern）定义如下：

Define the skeleton of an algorithm in an operation,deferring some steps to subclasses.Template
Method lets subclasses redefine certain steps of an algorithm without changing the algorithm's
structure.（定义一个操作中的算法的框架，而将一些步骤延迟到子类中。使得子类可以不改

变一个算法的结构即可重定义该算法的某些特定步骤。）

类图：

package syasuo.mobanfangfa;
/**
 * 抽象模板类
 * @author Administrator
 *
 */
public abstract class AbstractHummerModel {

	//启动
	protected abstract void start();
	//停止
	protected abstract void stop();
	//喇叭
	protected abstract void alarm();
	//跑车的引擎得会轰隆隆的响
	protected abstract void engineBoom();
	//
	/**
	 * 车子得会跑
	 * 注意：
	 * 		这里是体现模板方法模式的地方 
	 */
	final public void run(){
		this.start();
		this.engineBoom();
		if(this.isAlarm()){
			this.alarm();
		}
		this.stop();
	}
	
	//钩子方法 默认喇叭是不会响的 要按才会响
	protected boolean isAlarm(){
		return false;
	}
	
	
}

package syasuo.mobanfangfa;
/**
 * 悍马H2车型
 * @author Administrator
 *
 */
public class HummerH2Model extends AbstractHummerModel{

	@Override
	protected void start() {
		System.out.println("悍马H2启动了");
	}

	@Override
	protected void stop() {
		System.out.println("悍马H2停止了");
	}

	@Override
	protected void alarm() {
		System.out.println("悍马H2鸣喇叭滴滴滴滴");
	}

	@Override
	protected void engineBoom() {
		System.out.println("悍马H2引擎声隆隆隆隆");
	}

	/**
	 * 默认喇叭一直想
	 */
	protected boolean isAlarm(){
		return true;
	}
}

package syasuo.mobanfangfa;
/**
 * 悍马H1车型
 * @author Administrator
 *
 */
public class HummerH1Model extends AbstractHummerModel{

	private boolean alarmFlag = false; //要喇叭响
	@Override
	protected void start() {
		System.out.println("悍马H1启动了");
	}

	@Override
	protected void stop() {
		System.out.println("悍马H1停止了");
	}

	@Override
	protected void alarm() {
		System.out.println("悍马H1鸣喇叭哔哔哔哔");
	}

	@Override
	protected void engineBoom() {
		System.out.println("悍马H1引擎轰轰轰轰");
	}

	
	@Override
	protected boolean isAlarm() {
		
		return this.alarmFlag;
	}

	/**
	 * 要不要响喇叭 由驾驶人决定
	 * @param alarmFlag
	 */
	public void setAlarmFlag(boolean alarmFlag) {
		this.alarmFlag = alarmFlag;
	}
	
	
}

package syasuo.mobanfangfa;

import java.util.Scanner;


public class Main {

	public static void main(String[] args) {
		
		HummerH1Model h1Model = new HummerH1Model();
		Scanner scanner = new Scanner(System.in);
		System.out.println("请输入:");
		String str = scanner.next();
		if(str.equals("1"))
			h1Model.setAlarmFlag(true);
		
		h1Model.run();
		System.out.println("-------------------------------------");
		HummerH2Model h2Model = new HummerH2Model();
		h2Model.run();
		scanner.close();
	}
}