创建型——Builder模式

UML：

 

如何使用：

假设一个复杂对象由多个部件组成的。Builder模式是把复杂对象的创建和部件的创建分别开来，分别用Builder类和Director类来表示。

package com.lwf.create.builder;

public interface Builder {

	//用于复杂对象的创建，而其部件的组装在Director类中。
	void builderPartA();
	void builderPartB();
	Product getResult();
}

 

package com.lwf.create.builder;

public class ConcreateBuilder implements Builder {

	
	Part partA,partB;
	public void builderPartA() {
		partA = new Part();
	}

	public void builderPartB() {
		partB = new Part();
	}

	public Product getResult() {
		return new Product(partA,partB);
	}

}

 

 

package com.lwf.create.builder;

public class Director {
	//用于部件的组装
	Builder builder;
	public Director(Builder builder){
		this.builder = builder;
	}
	public void construct(){
		builder.builderPartA();
		builder.builderPartB();
	}


}

 

 

package com.lwf.create.builder;

public class Product {

	Part partA;
	Part partB;
	public Product(Part partA,Part partB){
		this.partA = partA;
		this.partB = partB;
	}
}

 

 

package com.lwf.create.builder;

public class Part {

}

 

 

package com.lwf.create.builder;

public class TestBuilder {

	public static void main(String[] args) {

		Builder builder = new ConcreateBuilder();
		Director director = new Director(builder);
		director.construct();//组装部件
		builder.getResult();//得到最终产品
	}

}

 

 代码见附件