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

Moveable

package com.bjsxt.spring.factory;

public interface Moveable {
	void run();
}

Car

package com.bjsxt.spring.factory;

public class Car implements Moveable {

	public void run() {
		System.out.println("冒着烟奔跑中car.......");
	}
}

Train

package com.bjsxt.spring.factory;

public class Train implements Moveable {

	@Override
	public void run() {
		System.out.println("小火车呜呜呜");
	}
}

BeanFactory

package com.bjsxt.spring.factory;

public interface BeanFactory {
	Object getBean(String id);
}

ClassPathXmlApplicationContext

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);
		  }

	}
	
	@Override
	public Object getBean(String id) {	
		return container.get(id);
	}

}

applicationContext.xml

<?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>

Test

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();
	}
}