设计模式--生成器模式

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                      设计模式--生成器模式

 

生成器模式原理

•度假计划生成项目设计

度假计划生成项目介绍

度假计划的因素：时间、门票、餐厅、住宿、特殊活动等

一个计划就是一个具体对象，要便于扩展

思考怎么做

复杂对象生成问题

•生成器模式原理

生成器模式：封装一个复杂对象构造过程，并允许按步骤构造。

•代码讲解

VacationDay

import java.util.ArrayList;
import java.util.Date;

public class VacationDay {
	private Date mDate;
	private String mHotels;
	private ArrayList<String> mTickets = null;
	private ArrayList<String> mEvents = null;

	public VacationDay(Date date) {
		mDate = date;
		mTickets = new ArrayList<String>();
		mEvents = new ArrayList<String>();
	}

	public void setDate(Date date) {
		mDate = date;
	}

	public void setHotel(String mHotels) {
		this.mHotels = mHotels;
	}

	public void addTicket(String ticket) {
		mTickets.add(ticket);
	}

	public void addEvent(String event) {
		mEvents.add(event);
	}

	public String showInfo() {
		StringBuilder stb = new StringBuilder();
		stb.append("Date:" + mDate.toString() + "\n");
		stb.append("Hotel:" + mHotels + "\n");
		stb.append("Tickets:" + mTickets.toString() + "\n");
		stb.append("Events" + mEvents.toString() + "\n");

		return stb.toString();
	}
}

Vacation 

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import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;

public class Vacation {
	private ArrayList<VacationDay> mVacationDayLst;
	private Date mStDate;
	private int mDays = 0;
	private VacationDay mVacationDay;

	public Vacation(String std) {
		mVacationDayLst = new ArrayList<VacationDay>();
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		try {
			mStDate = sdf.parse(std);
			mVacationDay = new VacationDay(mStDate);
			mVacationDayLst.add(mVacationDay);
			mDays++;
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public void setStDate(String std) {

		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		try {
			mStDate = sdf.parse(std);
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}

	public Date getStDate() {

		return mStDate;
	}

	public void addDay() {

		mVacationDay = new VacationDay(nextDate(mDays));
		mVacationDayLst.add(mVacationDay);
		mDays++;
	}

	public boolean setVacationDay(int i) {
		if ((i > 0) && (i < mVacationDayLst.size())) {
			mVacationDay = mVacationDayLst.get(i);
			return true;
		}
		mVacationDay = null;
		return false;
	}

	public void setHotel(String mHotels) {
		mVacationDay.setHotel(mHotels);
	}

	public void addTicket(String ticket) {
		mVacationDay.addTicket(ticket);
	}

	public void addEvent(String event) {
		mVacationDay.addEvent(event);
	}

	public void showInfo() {
		for (int i = 0, len = mVacationDayLst.size(); i < len; i++) {
			System.out.println("** " + (i + 1) + " day**");
			System.out.println(mVacationDayLst.get(i).showInfo());

		}
	}

	private Date nextDate(int n) {
		Calendar cal = Calendar.getInstance();
		cal.setTime(mStDate);
		cal.add(Calendar.DATE, n);
		return cal.getTime();
	}
}

AbsBuilder 

public abstract class AbsBuilder {

	public Vacation mVacation;

	public AbsBuilder(String std) {
		mVacation = new Vacation(std);
	}

	public abstract void buildvacation();

	public abstract void buildDay(int i);

	public abstract void addHotel(String hotel);

	public abstract void addTicket(String ticket);

	public abstract void addEvent(String tvent);

	public Vacation getVacation() {

		return mVacation;

	}

}

Builder3d

public class Builder3d extends AbsBuilder {

	public Builder3d(String std) {
		super(std);
		// TODO Auto-generated constructor stub

	}

	@Override
	public void buildDay(int i) {
		// TODO Auto-generated method stub

		mVacation.setVacationDay(i);

	}

	@Override
	public void addHotel(String hotel) {
		// TODO Auto-generated method stub
		mVacation.setHotel(hotel);
	}

	@Override
	public void addTicket(String ticket) {
		// TODO Auto-generated method stub
		mVacation.addTicket(ticket);
	}

	@Override
	public void addEvent(String event) {
		// TODO Auto-generated method stub
		mVacation.addEvent(event);
	}

	@Override
	public void buildvacation() {
		// TODO Auto-generated method stub
		addTicket("Plane Ticket");
		addEvent("Fly to Destination");
		addEvent("Supper");
		addEvent("Dancing");
		addHotel("Four Seasons");

		mVacation.addDay();
		addTicket("Theme Park");
		addEvent("Bus to Park");
		addEvent("lunch");
		addHotel("Four Seasons");

		mVacation.addDay();

		addTicket("Plane Ticket");
		addEvent("City Tour");
		addEvent("Fly to Home");

	}

}

Builder4d 

public class Builder4d extends AbsBuilder {

	public Builder4d(String std) {
		super(std);
		// TODO Auto-generated constructor stub

	}

	@Override
	public void buildDay(int i) {
		// TODO Auto-generated method stub

		mVacation.setVacationDay(i);

	}

	@Override
	public void addHotel(String hotel) {
		// TODO Auto-generated method stub
		mVacation.setHotel(hotel);
	}

	@Override
	public void addTicket(String ticket) {
		// TODO Auto-generated method stub
		mVacation.addTicket(ticket);
	}

	@Override
	public void addEvent(String event) {
		// TODO Auto-generated method stub
		mVacation.addEvent(event);
	}

	@Override
	public void buildvacation() {
		// TODO Auto-generated method stub
		addTicket("Plane Ticket");
		addEvent("Fly to Destination");
		addEvent("Supper");
		addHotel("Hilton");

		mVacation.addDay();
		addTicket("Zoo Ticket");
		addEvent("Bus to Zoo");
		addEvent("Feed animals");
		addHotel("Hilton");

		mVacation.addDay();
		addTicket("Beach");
		addEvent("Swimming");
		addHotel("Home inn");

		mVacation.addDay();
		addTicket("Plane Ticket");
		addEvent("Fly to Home");
	}

}

Director  

public class Director {
	private AbsBuilder builder;
	
	public Director(AbsBuilder builder)
	{
		this.builder=builder;
	}
	public void setBuilder(AbsBuilder builder)
	{
		this.builder=builder;
	}
	public void construct()
	{
		builder.buildvacation();
		builder.getVacation().showInfo();
	}
}

 MainTest 

public class MainTest {

	public static void main(String[] args) {

		Director mDirector = new Director(new Builder4d("2015-12-29"));

		mDirector.construct();

		mDirector.setBuilder(new Builder3d("2015-8-30"));
		mDirector.construct();
		testself() ;
	}

	public static void testself() {
		BuilderSelf builder = new BuilderSelf("2015-9-29");

		builder.addTicket("Plane Ticket").addEvent("Fly to Destination")
				.addEvent("Supper").addHotel("Hilton");

		builder.addDay().addTicket("Zoo Ticket").addEvent("Bus to Zoo")
				.addEvent("Feed animals").addHotel("Home Inn");

		builder.addDay();
		builder.addTicket("Beach");
		builder.addEvent("Swimming");
		builder.addHotel("Home inn");

		builder.addDay().addTicket("Plane Ticket").addEvent("Fly to Home");
		builder.getVacation().showInfo();
	}

}

生成器模式演化形式

•两种演化形式

省略抽象生成器类

BuilderSelf 

public class BuilderSelf {
	public Vacation mVacation;

	public BuilderSelf(String std) {
		mVacation = new Vacation(std);
		// TODO Auto-generated constructor stub

	}

	public BuilderSelf addDay() {
		// TODO Auto-generated method stub

		mVacation.addDay();
		return this;
	}

	public BuilderSelf buildDay(int i) {
		// TODO Auto-generated method stub

		mVacation.setVacationDay(i);
		return this;
	}

	public BuilderSelf addHotel(String hotel) {
		// TODO Auto-generated method stub
		mVacation.setHotel(hotel);
		return this;
	}

	public BuilderSelf addTicket(String ticket) {
		// TODO Auto-generated method stub
		mVacation.addTicket(ticket);
		return this;
	}

	public BuilderSelf addEvent(String event) {
		// TODO Auto-generated method stub
		mVacation.addEvent(event);
		return this;
	}

	public Vacation getVacation() {

		return mVacation;

	}
}

省略指导者类
 

•Java里的生成器

StringBuilder

Notification-NotificationCompat.Builder

生成器模式关键点

生成器模式与抽象工厂的差异
 

生成器模式和抽象工厂模式在功能上很相似，主要区别：

•生成器一般用来创建大的复杂的对象

•生成器模式强调的是一步步创建对象，可以改变步骤来生成不同的对象

•一般来说生成器模式中对象不直接返回