Android设计模式解析与实战－Builder模式

定义
* 将一个复杂对象的构建与它的表示分离，使得同样的构建过程可以创建不同的表示。

实例代码：

public class BuilderTest{

    abstract class Computer{

        String mBoard;
        String mScreen;
        String mOs;

        protected Computer(){}

        public void setBoard(String board){mBoard = board;}
        public void setScreen(String screen){mScreen = screen;}
        public abstract void setOs(String os);

        public String toString(){
            return "the os is " + mOs;
        }
    }

    class MacBook extends Computer{

        protected MacBook(){}

        public void setOs(String os){mOs = os;};
    }

    abstract class Builder{
        public abstract Builder builderBoard(String board);
        public abstract Builder builderScreen(String screen);
        public abstract Builder builderOs();
        public abstract Computer create();
    }

    class MacBookBuilder extends Builder{
        private Computer computer = new MacBook();

        public Builder builderBoard(String board){
            computer.setBoard(board);
            return this;
        }

        public Builder builderScreen(String screen){
            computer.setScreen(screen);
            return this;
        }

        public Builder builderOs(){
            computer.setOs("iOS");
            return this;
        }

        public Computer create(){
            return computer;
        }
    }

    public static void main(String[] args) {
        BuilderTest test = new BuilderTest();
        Builder builder = test.new MacBookBuilder();
        Computer com = builder.builderBoard("ha").builderScreen("dell").builderOs().create();
        System.out.println(com);
    }
    
}