Builder模式

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,隐藏具体构建过程.

 

Builder.java

package com.gary.designpattern.builder;

/**
 * 抽出整个build过程
 * @author gary
 * 
 */
public interface Builder {
	public void buildPartA();

	public void buildPartB();

	public void buildPartC();

	public Product getProduct();
}

 

BuilderImplA.java

package com.gary.designpattern.builder;

/**
 * 不同的Build具体实现
 * @author gary
 * 
 */
public class BuilderImplA implements Builder {

	private Product productA = new Product();

	@Override
	public void buildPartA() {
		System.out.println("building A in BuilderImplA");
		productA.addPart("A");
	};

	@Override
	public void buildPartB() {
		System.out.println("building B in BuilderImplA");
		productA.addPart("B");
	};

	@Override
	public void buildPartC() {
		System.out.println("building C in BuilderImplA");
		productA.addPart("C");
	}

	@Override
	public Product getProduct() {
		return productA;
	};

}

 

BuilderImplB.java

package com.gary.designpattern.builder;

/**
 * 不同的Build具体实现
 * @author gary
 *
 */
public class BuilderImplB implements Builder {
	
	private Product productB = new Product();

	@Override
	public void buildPartA() {
		System.out.println("building A in BuilderImplB");
		productB.addPart("a");
	};

	@Override
	public void buildPartB() {
		System.out.println("building B in BuilderImplB");
		productB.addPart("b");
	};

	@Override
	public void buildPartC() {
		System.out.println("building C in BuilderImplB");
		productB.addPart("c");
	}

	@Override
	public Product getProduct() {
		return productB;
	};

}

 

Director.java

package com.gary.designpattern.builder;

/**
 * 控制整体建造过程,隐藏建造过程中每一步的具体实现
 * @author gary
 *
 */
public class Director {
	
	private Builder builder;

	/**
	 * 需要建造什么样的对象
	 * @param builder
	 */
	public Director(Builder builder) {
		this.builder = builder;
	}

	public void build() {
		builder.buildPartA();
		builder.buildPartB();
		builder.buildPartC();
	}
	
	public Product getProduct(){
		return builder.getProduct();
	}

}

 

Product.java

package com.gary.designpattern.builder;

public class Product{

	private String data = "";
	
	public void addPart(String part) {
		data += part;
	}

	public void printProduct() {
		System.out.println(data);
	}

}

 

Test.java

package com.gary.designpattern.builder;

/**
 * 测试
 * @author gary
 *
 */
public class Test {
	public static void main(String[] args) {
		BuilderImplA builderA = new BuilderImplA(); 
		Director directorA = new Director(builderA);   
		directorA.build();
		Product productA = directorA.getProduct();
		productA.printProduct();
		
		System.out.println("========split=======");
		
		BuilderImplB builderB = new BuilderImplB(); 
		Director directorB = new Director(builderB);   
		directorB.build();
		Product productB = directorB.getProduct();
		productB.printProduct();
	}
}

 

评论

1 楼 eric_shi 2011-02-11  

为什么 这么多人踩