創(chuàng)建者模式主要是為了所謂的高聚合，解耦合，遇到多種配件于一身的情況的時候，放在實體類里面不合適，放在工廠類也不合適，所以就添加了一個創(chuàng)建者類，專門對相應(yīng)的零件進行組裝，如同汽車了N中配件，同時要是各種配件互相聯(lián)系的話也在這個Builder里面一并做了。

明天準備去爬山，這個原理圖就再補上吧：

今天把uml補上了，不過對于uml初學(xué)的我就亂亂的先隨便畫一個吧，等以后慢慢入門了在斟酌里面的錯誤和細節(jié)：

下面是我自己攢出來的例子（回來的時候著急，把書忘教室了，不知道書上怎么寫的，不過明顯記得一處錯誤，構(gòu)造器也加上了一個void），為了在Builder里面優(yōu)化一下，用了一下反射，這樣就可以直接通過多態(tài)來實現(xiàn)對于派生類中的實體類進行初始化并且操作了，簡單的實現(xiàn)電腦的組裝：通過工廠類實例化Computer的父類指向子類的實例，然后在Builder里面添加一個工廠類的私有變量，通過構(gòu)造器把要穿件的Computer實例傳入Builder，然后對其進行解析，反射得到路徑，對其派生類里面的方法進行反射得到相應(yīng)的配件的集成，轉(zhuǎn)配完成。少說多做：

    package com.designpattern.builder;

public interface Mouse {
	public void add();
}
  

    package com.designpattern.builder;

public interface Monitor {
	public void add();
}

  

    package com.designpattern.builder;

public interface Keyboard {
	public void add();
}

  

    package com.designpattern.builder;

public interface Displayer {
	public void add();
}

  

    package com.designpattern.builder;

public interface Factory {
	public Computer buildComputer();
}

  

    package com.designpattern.builder;

public interface Computer {
	public void add();
}

  

    package com.designpattern.builder;

public class AcerMouse implements Mouse {

	@Override
	public void add() {
		System.out.println("add AcerMouse");
	}

}

  

    package com.designpattern.builder;

public class AcerMonitor implements Monitor {

	@Override
	public void add() {
		System.out.println("add AcerMonitor");
	}

}

  

    package com.designpattern.builder;

public class AcerKeyboard implements Keyboard {

	@Override
	public void add() {
		System.out.println("add AcerKeyboard");
	}

}

  

    package com.designpattern.builder;

public class AcerDisplayer implements Displayer {

	@Override
	public void add() {
		System.out.println("add AcerDisplayer");
	}

}

  

    package com.designpattern.builder;

public class AcerFactory implements Factory {
	
	@Override
	public Computer buildComputer() {
		return new Acer();
	}
}

  

    package com.designpattern.builder;

public class Acer implements Computer {

	@Override
	public void add() {
		System.out.println("builder Acer");
	}

}

  

    package com.designpattern.builder;

import java.lang.reflect.Method;

public class Builder {
	private Factory factory;

	public Builder(Factory factory) {
		this.factory = factory;
	}

	public void builder() throws Exception {
		factory.buildComputer().add();
		String computer = factory.getClass().toString();
		computer = computer.substring(6, computer.length() - 7);

		// build Mouse
		Class c = Class.forName(computer + "Mouse");
		Mouse mouse = (Mouse) c.newInstance();
		Method method = c.getMethod("add", null);
		method.invoke(mouse, null);

		// build Keyboard
		c = Class.forName(computer + "Keyboard");
		Keyboard keyboard = (Keyboard) c.newInstance();
		method = c.getMethod("add", null);
		method.invoke(keyboard, null);

		// build Displayer
		c = Class.forName(computer + "Displayer");
		Displayer displayer = (Displayer) c.newInstance();
		method = c.getMethod("add", null);
		method.invoke(displayer, null);

		// build Monitor
		c = Class.forName(computer + "Monitor");
		Monitor monitor = (Monitor) c.newInstance();
		method = c.getMethod("add", null);
		method.invoke(monitor, null);

		System.out.println("build complete");
	}
}

  

    package com.designpattern.builder;

public class Client {
	public static void main(String[] args) {
		try {
			new Builder(new AcerFactory()).builder();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

  

設(shè)計模式 （四）創(chuàng)建者模式(Builder)