spring1 selfApplicationContext used

package junit.test;

public class BeanDefinition {
	private String id;
	private String className;
	
	public BeanDefinition(String id,String className){
		this.id = id;
		this.className = className;
	}
	
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getClassName() {
		return className;
	}
	public void setClassName(String className) {
		this.className = className;
	}
	
}

package junit.test;

import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.XPath;
import org.dom4j.io.SAXReader;

public class ItcastClassPathXMLApplicationContext {
	private List<BeanDefinition> beanDefines = new ArrayList<BeanDefinition>();
	private Map<String,Object> singletons = new HashMap<String , Object>();
	public ItcastClassPathXMLApplicationContext(String filename){
		this.readXML(filename);
		this.instanceBeans();
	}
	/**
	 * 完成bean實例化
	 */
	private void instanceBeans() {
		for(BeanDefinition beanDefinition:beanDefines){
			try {
				if(beanDefinition.getClassName()!=null&&!"".equals(beanDefinition.getClassName().trim()))
					singletons.put(beanDefinition.getId(), Class.forName(beanDefinition.getClassName()).newInstance());
			} catch (InstantiationException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (ClassNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	
	}
/**
 * 讀取xml配置文件
 * @param filename
 */
	private void readXML(String filename) {
		// TODO Auto-generated method stub
		SAXReader saxReader = new SAXReader();
		Document document = null;
		try{
			URL xmlpath = this.getClass().getClassLoader().getResource(filename);
			document = saxReader.read(xmlpath);
			Map<String,String> nsMap = new HashMap<String,String>();
			nsMap.put("ns", "http://www.springframework.org/schema/beans");//加入命名空間
			XPath xsub = document.createXPath("//ns:beans/ns:bean");//創建beans/bean查詢路徑
			xsub.setNamespaceURIs(nsMap);//設置命名空間
			List<Element> beans = xsub.selectNodes(document);//獲取文檔下所有bean節點
			for(Element element:beans){
				String id = element.attributeValue("id");//獲取id屬性
				String clazz = element.attributeValue("class");//獲取class屬性
				BeanDefinition beanDefine = new BeanDefinition(id,clazz);
				beanDefines.add(beanDefine);
			}
		}catch(Exception e){
			e.printStackTrace();
		}
	}
	
	public Object getBean(String beanName){
		return this.singletons.get(beanName);
	}
}

package junit.test;


import org.junit.BeforeClass;
import org.junit.Test;

import cn.itcast.service.PersonService;

public class SpringTest {

	@BeforeClass
	public static void setUpBeforeClass() throws Exception {
	}
	
	@Test
	public void instanceSpring(){
		ItcastClassPathXMLApplicationContext ctx = new ItcastClassPathXMLApplicationContext("beans.xml");
		PersonService personService = (PersonService)ctx.getBean("personService");
		personService.save();
		
		
	}

}

package cn.itcast.service;

public interface PersonService {

	public abstract void save();

}

package cn.itcast.service.impl;

import cn.itcast.dao.PersonDao;
import cn.itcast.service.PersonService;

public class PersonServiceBean implements PersonService {
	/* (non-Javadoc)
	 * @see cn.itcast.service.impl.PersonService#save()
	 */
	public void save(){
		System.out.println("Iam save()");
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
		xsi:schemaLocation="http://www.springframework.org/schema/beans
			http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
			<bean id="personService" class="cn.itcast.service.impl.PersonServiceBean" >
			</bean>
</beans>