Builder

1類圖

1計算機抽象類即Product角色

public abstract class Computer {
    protected String mBoard;
    protected String mDisplay;
    protected String mOS;
    protected Computer(){}
    public void setBoard(String mBoard) {
        this.mBoard = mBoard;
    }
    public void setDisplay(String mDisplay) {
        this.mDisplay = mDisplay;
    }
    public abstract void setOS();
    @Override
    public String toString() {
        // TODO Auto-generated method stub
        return "Computer [mBoard=" + mBoard + ", mDisplay=" + mDisplay+ ", mOS=" + mOS + "]";
    }
}

2具體的Computer類

public class Macbook extends Computer {

    protected Macbook(){}

    @Override
    public void setOS() {
        // TODO Auto-generated method stub
        mOS = "Mac OS X 10.10";
    }

}

3抽象Builder類

public abstract class Builder {
    public abstract void buildBoard(String board);
    public abstract void buildDisplay(String display);
    public abstract void buildOS();
    public abstract Computer create(); 
}

4具體Builder類

public class MacbookBuilder extends Builder {

    private Computer mComputer = new Macbook();

    @Override
    public void buildBoard(String board) {
        // TODO Auto-generated method stub
        mComputer.setBoard(board);
    }

    @Override
    public void buildDisplay(String display) {
        // TODO Auto-generated method stub
        mComputer.setDisplay(display);
    }

    @Override
    public void buildOS() {
        // TODO Auto-generated method stub
        mComputer.setOS();
    }

    @Override
    public Computer create() {
        // TODO Auto-generated method stub
        return mComputer;
    }

}

5Director 負責構造Computer

public class Director {
    Builder mBuilder = null;
    public Director(Builder builder) {
        // TODO Auto-generated constructor stub
        mBuilder = builder;
    }
    public void construct(String board,String display){
        mBuilder.buildBoard(board);
        mBuilder.buildDisplay(display);
        mBuilder.buildOS();
    }
}

6測試

public class test {
    public static void main(String[] args) {
        //構造器
        Builder builder = new MacbookBuilder();
        Director pcDirector = new Director(builder);
        //封裝過程
        pcDirector.construct("英特爾主板", "Retina顯示屏");
        //構建計算機 輸出相關信息
        System.out.println(builder.create().toString());
    }
}