spring依赖注入的简单实现

bean配置文件将就spring的：

applicationContext.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:context="http://www.springframework.org/schema/context"
	 xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" 
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

	<bean id="user" class="org.forever.ioc.entities.User">
		<property name="username" value="forever"/>
		<property name="nickNames">
			<list>
				<value>传说</value>
				<value>神话</value>
			</list>
		</property>
	</bean>

</beans>

 实体类User：

package org.forever.ioc.entities;

public class User {

	private String username;
	private String[] nickNames;
	
	
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String[] getNickNames() {
		return nickNames;
	}
	public void setNickNames(String[] nickNames) {
		this.nickNames = nickNames;
	}
	
	
	
}

 容器类Application：

package org.forever.ioc.context;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.forever.ioc.entities.User;

//容器
public class ApplicationContext {

	private String resourceName = "applicationContext.xml";
	private Map<String, Object> map = new HashMap<String, Object>();

	public ApplicationContext() {
		readxml();
	}

	public ApplicationContext(String resourceName) {
		this.resourceName = resourceName;
		readxml();
	}

	private void readxml() {
		// 读取配置文件
		SAXReader saxReader = new SAXReader();
		try {
			Document document = saxReader.read(ApplicationContext.class
					.getClassLoader().getResourceAsStream(
							resourceName));
			
			Element root = document.getRootElement();

			for (Object item : root.elements()) {
				Element element = (Element) item;
				String id = element.attribute("id").getText();
				String className = element.attribute("class").getText();
				Class clazz = Class.forName(className);
				Object instance = clazz.newInstance();
				
				// 注入属性的值
				for (Object property_ : element.elements("property")) {
					Element elementProperty = (Element) property_;
					Attribute attrName = elementProperty.attribute("name");
					Attribute attrValue = elementProperty.attribute("value");
					// 反射获取这个字段的类型
					Field field = clazz.getDeclaredField(attrName.getText());
					Type type = field.getGenericType();
					
					String methodName = "set" + attrName.getText().substring(0, 1).toUpperCase()
					+ attrName.getText().substring(1);
					//获取set方法
					Method method = clazz.getDeclaredMethod(methodName,(Class)type);
					// 如果该字段是一个数组类型
					if (((Class)type).isArray()) {
						List<Element> valueList = elementProperty.element("list").elements("value");
						String[]args = new String[valueList.size()];
						for (int i = 0; i < valueList.size(); i++) {
							args[i]=valueList.get(i).getText();
						}
						method.invoke(instance,new Object[]{args});
					} else {
						method.invoke(instance, attrValue.getText());
					}
				}
				
				map.put(id, instance);
			}

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public Object getBean(String beanName) {
		return map.get(beanName);
	}

	public static void main(String[] args) {

		ApplicationContext context = new ApplicationContext();
		User user = (User) context.getBean("user");
		System.out.println("用户的名字：" + user.getUsername());
		System.out.println("用户的昵称：");
		for (String nickName : user.getNickNames()) {
			System.out.println(nickName);
		}
	}
}

  暂时未实现bean中实体的引用，有空再重构