spring IOC 反射加载demo

sPRing模拟 xml文件装载bean

简单的demo 用于更清楚的了解 spring的注入原理。spring IOC都知道通过java的反射 但是具体的反射 ，怎么实现的？。。。相信就是已经工作的小伙伴好多也不知道他的具体实现方式

结构图 model 当做service 简单的demo 没有太规范

xml配置文件

<?xml version="1.0" encoding="UTF-8"?><beans>	<bean id="user" class="com.spring.model.Student">	</bean>    <bean id="person" class="com.spring.model.Person">        <property name="age" value="1111"/>        <property name="addres" value="BJ"/>        <property name="name" value="tom"/>        <property name="student" ref="user"/>    </bean>    <bean id="A" class="com.spring.model.A">    	<property name="person" ref="person"/>    </bean></beans>
Model代码
package com.spring.model;public class A {	String username;	String pas;		Person person;	public String getUsername() {		return username;	}	public void setUsername(String username) {		this.username = username;	}	public String getPas() {		return pas;	}	public void setPas(String pas) {		this.pas = pas;	}	public Person getPerson() {		return person;	}	public void setPerson(Person person) {		this.person = person;	}		public void sysGet() {		System.out.println(person.toString());	}	}package com.spring.model;import java.lang.reflect.Method;public class Person implements java.io.Serializable{	/**	 * 	 */	private static final long serialVersionUID = 1L;	private String name;	private int age;	private String addres;		private Student student;		public Person() {}		public Student getStudent() {		return student;	}	public void setStudent(Student student) {		this.student = student;	}	public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public int getAge() {		return age;	}	public void setAge(int age) {		this.age = age;	}	public String getAddres() {		return addres;	}	public void setAddres(String addres) {		this.addres = addres;	}		public static void main(String[] args) throws NoSuchMethodException, SecurityException {		Person person = new Person();		Student student = new Student();		Class<?> tClass = student.getClass();		Method method = person.getClass().getMethod("setStudent",tClass);		System.err.println(method);	}	@Override	public String toString() {		return "Person [name=" + name + ", age=" + age + ", addres=" + addres + ", student=" + student + "]";	}		}package com.spring.model;import java.io.Serializable;public class Student implements Serializable {	int SttNum;	int clazz;	public int getSttNum() {		return SttNum;	}	public void setSttNum(int sttNum) {		SttNum = sttNum;	}	public int getClazz() {		return clazz;	}	public void setClazz(int clazz) {		this.clazz = clazz;	}}
用于存储xml 信息的对象
package com.spring;import java.util.List;import java.util.Properties;public class Bean {	private String name;	private String className;		private List<Property> properties;		public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public String getClassName() {		return className;	}	public void setClassName(String className) {		this.className = className;	}	public List<Property> getProperties() {		return properties;	}	public void setProperties(List<Property> properties) {		this.properties = properties;	}	}package com.spring;public class Property {	private String name;	private Object value;	private String ref;	public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public Object getValue(){		return value;	}		public void setValue(Object value) {		this.value = value;	}	public String getRef() {		return ref;	}	public void setRef(String ref) {		this.ref = ref;	}	}
解析xml 的ConfigManager 返回一个Map对象
package com.spring;import org.dom4j.Document;import org.dom4j.Element;import org.dom4j.io.SAXReader;import java.io.InputStream;import java.io.StringReader;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;public class ConfigManager {	static Document document =null;	static Map<String, Object> map = new HashMap<String, Object>();	public static Map<String, Object> getConfig(String path){		String xpath = "//bean";	        try {	        	InputStream inputStream = ConfigManager.class.getResourceAsStream(path);	            SAXReader reader = new SAXReader();	            document = reader.read(inputStream);	            List<Element> list =  document.selectNodes(xpath);	            for(Element element : list){	            	Bean bean = new Bean();	            	String name = element.attributeValue("id");	            	bean.setName(name);	            	bean.setClassName(element.attributeValue("class"));	            	List<Property> lProperties =new ArrayList<Property>();	            	List<Element> children = element.elements("property");	            	for(Element element2 : children){	            		Property property = new Property();	            		property.setName(element2.attributeValue("name"));	            		property.setValue(element2.attributeValue("value"));	            		property.setRef(element2.attributeValue("ref"));	            		lProperties.add(property);	            	} 	            	bean.setProperties(lProperties);	            		            	map.put(name, bean);	            }	            return map;	        } catch (Exception e1) {	        	e1.printStackTrace();	        	return null;	        }	       	}}测试类 和用于注入属性的静态方法BeanSet 参数 ConfigManager 返回的map对象
package com.spring;import java.lang.reflect.Method;import java.util.Map;import java.util.concurrent.ConcurrentHashMap;import org.apache.commons.beanutils.BeanUtils;import org.apache.commons.lang.StringUtils;import com.spring.model.A;import com.spring.model.Person;public class test {		static ConcurrentHashMap<String,Object> applicActionContext = new ConcurrentHashMap<String,Object>(); //类似于 spring 的上下文存储bean对象	public static void main(String[] args) throws Exception {		Map<String, Object> map =  ConfigManager.getConfig("/spring-test.xml");		BeanSet(map);				Person person = (Person) applicActionContext.get("person");		A a =(A) applicActionContext.get("A");		a.sysGet();	}		public static void BeanSet(Map<String, Object> map) throws Exception{		for (Map.Entry<String, Object> entry : map.entrySet()) {  			System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());  			Bean bean = (Bean) entry.getValue();			Object beanObj = Class.forName(bean.getClassName()).newInstance();			applicActionContext.put(bean.getName(), beanObj);			for(Property property : bean.getProperties()){				String methodName = "set" + property.getName().substring(0, 1).toUpperCase() + property.getName().substring(1);				if(property.getValue()!=null){//属性注入					BeanUtils.setProperty(beanObj, property.getName(), property.getValue());				}				if(StringUtils.isNotBlank(property.getRef())){//依赖注入					Bean vbBean =  (Bean) map.get(property.getRef());					Object o = null;					if(null==applicActionContext.get(vbBean.getName())){						o = Class.forName(vbBean.getClassName()).newInstance();						applicActionContext.put(vbBean.getName(),o);					}else {						o = applicActionContext.get(vbBean.getName());					}					Method method = beanObj.getClass().getMethod(methodName, o.getClass());					method.invoke(beanObj, o);				}			}					}  			}}
运行可以看到 我们的依赖注入合传递依赖都已经注入到我们的 A对象里面 简单的demo 用于更清楚的了解 spring的注入原理。spring IOC都知道demo 下载地址