学习Spring(二) 调用静态工厂方法创建Bean

1,创建抽象的产品类

package com.robert.spring.shop;

public abstract class Product {

}

2，创建具体产品类

package com.robert.spring.shop;

public class Battery extends Product {
	private String name;
	private double price;

	public Battery(String name, double price) {
		this.name = name;
		this.price = price;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public double getPrice() {
		return price;
	}

	public void setPrice(double price) {
		this.price = price;
	}

	@Override
	public String toString() {
		return "name=" + name + "\tprice=" + price;
	}
}

package com.robert.spring.shop;

public class Disc extends Product {
	
	private String name;
	private double price;
	
	public Disc(String name,double price){
		this.name = name;
		this.price = price;
	}
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}

	public double getPrice() {
		return price;
	}

	public void setPrice(double price) {
		this.price = price;
	}

	@Override
	public String toString() {
		return "name="+name+"\tprice="+price;
	}
	
	
}

3，创建工厂类

package com.robert.spring.shop;

public class ProductCreator {
	
	public static Product createProduct(String productId){
		if("aaa".equals(productId)){
			return new Battery("AAA",2.5);
		} else if("cdrw".equals(productId)){
			return new Disc("CD-RW",1.5);
		}
		throw new IllegalArgumentException("Unknown product");
	}
}

4，创建测试类

package com.robert.spring.shop;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class ProductTest {
	
	public static void main(String[] args) {
		ApplicationContext context = new ClassPathXmlApplicationContext("classpath:/spring/products.xml");
		Product battery = (Battery)context.getBean("aaa");
		System.out.println(battery.toString());
		
		Product cdrw = (Disc)context.getBean("cdrw");
		System.out.println(cdrw.toString());
	}
}

Spring配置文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<!-- Application context definition. -->
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
	xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:aop="http://www.springframework.org/schema/aop"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans.xsd
	http://www.springframework.org/schema/context
	http://www.springframework.org/schema/context/spring-context.xsd
	http://www.springframework.org/schema/tx
	http://www.springframework.org/schema/jdbc
	http://www.springframework.org/schema/aop
	http://www.springframework.org/schema/jdbc/spring-jdbc.xsd"
	default-autowire="byName">
	
	<bean id="aaa" class="com.robert.spring.shop.ProductCreator" factory-method="createProduct">
		<constructor-arg value="aaa"/>
	</bean>
	
	<bean id="cdrw" class="com.robert.spring.shop.ProductCreator" factory-method="createProduct">
		<constructor-arg value="cdrw"/>
	</bean>
</beans>

输出结果为：

name=AAA price=2.5
name=CD-RW price=1.5