设计模式四--建造者模式

设计模式四--建造者模式

一、定义

将一个复杂对象呢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。

 

二、优点

封装性

建造者独立，容易扩展

 

三、原理图

 

Product代表具体的产品

ConcreteBuilder是这些产品建造过程的一个接口

Builder是这些产品的具体建造实例，实现ConcreteBuilder接口

Director包含不同的Builder，负责构造各个产品

 

四、实例

1、Computer

抽象的计算机类

public abstract class Computer {
    private String type;//型号
    private String cpu;

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public String getCpu() {
        return cpu;
    }

    public void setCpu(String cpu) {
        this.cpu = cpu;
    }
    
}

 

2、T410

继承了Computer类

代表T410电脑

package definition;

public class T410 extends Computer {
    private String graphicCard;//显卡
    public T410(){
        this.setType("ThinkPad T410");
    }
    public String getGraphicCard() {
        return graphicCard;
    }
    public void setGraphicCard(String graphicCard) {
        this.graphicCard = graphicCard;
    }
    
    
    //输出型号，内存和显卡
    public String toString() {
        return "T410 [getType()=" + getType() + ", getCpu()=" + getCpu() + ", graphicCard=" + graphicCard + "]";
    }
    
}

 

3、X201

继承了Computer类

代表X201电脑

public class X201 extends Computer {

    public X201() {
        this.setType("ThinkPad X201");
    }

    //显示型号和cpu
    public String toString() {
        return "X201 [getType()=" + getType() + ", getCpu()=" + getCpu() + "]";
    }

}

 

4、ComputerBuilder

接口类，用于建造电脑

public interface ComputerBuilder {
    void buildCpu();//建造cpu
    void buildGraphicCard();//建造显卡
    
    Computer getResult();//得到建造好的计算机
}

 

5、T410Builder

实现ComputerBuilder接口

T410的具体实现

public class T410Builder implements ComputerBuilder {
    private T410 computer =new T410();

    public void buildCpu() {
        computer.setCpu("i5-450");
    }
    
    public void buildGraphicCard(){
        computer.setGraphicCard("Nvidia NVS 3100M");
    }

    public Computer getResult() {
        
        return computer;
    }

}

 

6、X201Builder

实现ComputerBuilder接口

X201的具体实现

public class X201Builder implements ComputerBuilder {

    private X201 computer = new X201();
    public void buildCpu() {
        computer.setCpu("i3-350");
    }

    public Computer getResult() {
        return computer;
    }

    public void buildGraphicCard() {
        // TODO Auto-generated method stub
        
    }

}

 

7、ComputerDirector

Director包含不同的Builder，负责构造各个产品

public class ComputerDirector {
    ComputerBuilder builder;

    //建造T410号机器
    public T410 constructT410() {
        builder=new T410Builder();
        builder.buildCpu();
        builder.buildGraphicCard();
        return (T410)builder.getResult();
    }

    //建造X201号机器
    public X201 constructX201() {
        builder=new X201Builder();
        builder.buildCpu();
        return (X201)builder.getResult();
    }

}

 

8、ComputerTest

具体的测试类

 

public class ComputerTest {

    public static void main(String[] args) {
        ComputerDirector computerDirector=new ComputerDirector();
        Computer t410=computerDirector.constructT410();
        System.out.println(t410);
        
        System.out.println("----------------------------");
        
        Computer x201=computerDirector.constructX201();
        System.out.println(x201);
    }

}

 

五、实验结果

T410 [getType()=ThinkPad T410, getCpu()=i5-450, graphicCard=Nvidia NVS 3100M]

----------------------------

X201 [getType()=ThinkPad X201, getCpu()=i3-350]