Java学习笔记——设计模式之九.建造者模式

 建造者模式（Builder）,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。

Product类：

package cn.happy.design_pattern._09builder;

import java.util.ArrayList;
import java.util.List;

public class Product {

    List<String> parts = new ArrayList<>();
    
    public void add(String part){
        parts.add(part);
    }
    
    public void show(){
        System.out.println("创建产品...");
        for (String item : parts) {
            System.out.println(item);
        }
    }
}

Builder类：

package cn.happy.design_pattern._09builder;

public abstract class Builder {

    public abstract void BuildPartA();
    public abstract void BuildPartB();
    public abstract Product GetResult();
}

Builder子类：

package cn.happy.design_pattern._09builder;

public class ConcreteBuilder1 extends Builder {

    private Product product = new Product();
    @Override
    public void BuildPartA() {
        product.add("部件A");

    }

    @Override
    public void BuildPartB() {
        product.add("部件B");

    }

    @Override
    public Product GetResult() {
        // TODO Auto-generated method stub
        return product;
    }

}

public class ConcreteBuilder2 extends Builder {

    private Product product = new Product();
    @Override
    public void BuildPartA() {
        product.add("部件X");

    }

    @Override
    public void BuildPartB() {
        product.add("部件Y");

    }

    @Override
    public Product GetResult() {
        // TODO Auto-generated method stub
        return product;
    }

}

Director类：

package cn.happy.design_pattern._09builder;

public class Director {

    public void Construct(Builder builder){
        builder.BuildPartA();
        builder.BuildPartB();
    }
}

测试类：

package cn.happy.design_pattern._09builder;

public class Mmain {
    public static void main(String[] args) {
        Director director = new Director();
        Builder b1 = new ConcreteBuilder1();
        Builder b2 = new ConcreteBuilder2();
        director.Construct(b1);
        b1.GetResult().show();
        director.Construct(b2);
        b2.GetResult().show();
    }
}