[Java] 设计模式之工厂系列 04 （自定义模拟 spring 读取xml文件 beanFactory）

package com.bjsxt.spring.factory;public interface Moveable {void run();
}

package com.bjsxt.spring.factory;public class Car implements Moveable {public void run() {System.out.println("冒着烟奔跑中car.......");}
}

package com.bjsxt.spring.factory;public class Train implements Moveable {@Overridepublic void run() {System.out.println("小火车呜呜呜");}
}

package com.bjsxt.spring.factory;public interface BeanFactory {Object getBean(String id);
}

package com.bjsxt.spring.factory;import java.util.HashMap;
import java.util.List;
import java.util.Map;import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;
import org.jdom.xpath.XPath;public class ClassPathXmlApplicationContext implements BeanFactory  {private Map<String, Object> container = new HashMap<String, Object>();public ClassPathXmlApplicationContext(String fileName) throws Exception{SAXBuilder sb = new SAXBuilder();Document doc = sb.build(this.getClass().getClassLoader().getResourceAsStream(fileName));Element root = doc.getRootElement();List list = XPath.selectNodes(root, "/beans/bean");System.out.println(list.size());for (int i = 0; i < list.size(); i++) { Element bean = (Element) list.get(i);String id = bean.getAttributeValue("id");String clazz = bean.getAttributeValue("class");Object o = Class.forName(clazz).newInstance();container.put(id, o);System.out.println(id + " " + clazz);}}@Overridepublic Object getBean(String id) {	return container.get(id);}}

<?xml version="1.0" encoding="UTF-8"?>
<beans><bean id="v" class="com.bjsxt.spring.factory.Train"></bean><!--  //v=com.bjsxt.spring.factory.Car  --></beans>

package com.bjsxt.spring.factory;import java.io.IOException;
import java.util.Properties;public class Test {/*** @param args* @throws IOException */public static void main(String[] args) throws Exception {BeanFactory f = new ClassPathXmlApplicationContext("com/bjsxt/spring/factory/applicationContext.xml");Object o = f.getBean("v");Moveable m = (Moveable)o;m.run();}
}