Builder模式

最新推荐文章于 2025-04-27 23:52:07 发布

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本文详细介绍了Builder模式的概念及其在软件设计中的应用。通过具体的代码示例，展示了如何利用Builder模式来构建复杂对象，同时保持良好的封装性和灵活性。文章还讨论了该模式的角色划分以及其主要优点。

Builder模式的UML图

类图

时序图

Builder模式的角色

Director ：调用具体的Builder去构建对象

Builder : 抽象接口，规范产品对象的各个组成部分的构建

ConcreteBuilder : 实现builder类抽象接口，建造过程完成后，返回产品

Product : 建造的产品对象

Builder模式的优点

调用者无需知道构造细节
可以更精细的控制构建过程
将构建过程和部件解耦
使用不同的builder，相同的构建过程，能够产生不同的对象

一个Builder模式

Director

public class Director {
	
	private Builder builder;
	
	public Director(Builder b) {
		builder = b;
	}
	
	public void construct(){
		
		builder.buildFloor();
		builder.buildHousetop();
		builder.buildWall();
		
	}

}

Builder

public interface Builder {
	
	public void buildFloor();
	
	public void buildWall();
	
	public void buildHousetop();
	
	public House getResult();

}

ConcreateBuilder1

public class PingFangBuilder implements Builder {
	
	private House house = new House();

	@Override
	public void buildFloor() {
		house.setFloor("平房->地板");
	}

	@Override
	public void buildWall() {
		house.setWall("平房->墙");
	}

	@Override
	public void buildHousetop() {
		house.setHousetop("平房->房顶");
	}

	@Override
	public House getResult() {
		return house;
	}

}

ConcreteBuilder2

public class GongyuBuilder implements Builder {
	
	private House house = new House();

	@Override
	public void buildFloor() {
		house.setFloor("公寓地板");
	}

	@Override
	public void buildWall() {
		house.setWall("公寓墙");
	}

	@Override
	public void buildHousetop() {
		house.setHousetop("公寓屋顶");
	}

	@Override
	public House getResult() {
		return house;
	}

}

Product

public class House {
	
	private String floor;
	
	private String wall;
	
	private String housetop;

	public String getFloor() {
		return floor;
	}

	public void setFloor(String floor) {
		this.floor = floor;
	}

	public String getWall() {
		return wall;
	}

	public void setWall(String wall) {
		this.wall = wall;
	}

	public String getHousetop() {
		return housetop;
	}

	public void setHousetop(String housetop) {
		this.housetop = housetop;
	}

}

Client

public class MainClass {

	public static void main(String[] args) {

		Builder builder1 = new PingFangBuilder();
		Director director1 = new Director(builder1);
		director1.construct();
		House house1 = builder1.getResult();
		
		GongyuBuilder builder2 = new GongyuBuilder();
		Director director2 = new Director(builder2);
		director2.construct();
		House house2 = builder2.getResult();
	}

}