package com.pri.test;import com.pri.factory.BeanFactory;
import com.pri.service.UserService;
import org.junit.Test;public class BeanFactoryTest {@Testpublic void test(){BeanFactory beanFactory = BeanFactory.getBeanFactory();UserService user = (UserService)beanFactory.getBean("user");user.save();}
}

<?xml version="1.0" encoding="UTF-8"?>
<beans ><bean id="user" class="com.pri.service.impl.UserServiceImpl01"><property name="name" value="李四"/></bean>
</beans>

package com.pri.service.impl;import com.pri.service.UserService;

public class UserServiceImpl01 implements UserService{private String name;public String getName() { return name;}public void setName(String name) { this.name = name;}@Overridepublic void save(){System.out.println("UserService被调用........::"+name);}
}

package com.pri.factory;import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class BeanFactory {/*** 私有化构造,禁止以new的方式获取BeanFactory实例*/private BeanFactory(){}/*** 静态内部类,保证只有一个BeanFactory*/static class SingleBeanFactory{static BeanFactory BEANFACTORY = new BeanFactory();}/*** 对外提供一个获取BeanFactory方法* @return*/public static BeanFactory getBeanFactory(){return SingleBeanFactory.BEANFACTORY;}public Object getBean(String id) {try {Element element = getElement(id);String classPath = element.attribute("class").getValue();//根据类的全限定名创建Class对象Class<?> clazz = Class.forName(classPath);//创建实例Object obj = clazz.newInstance();//为bean对象赋值
            setAttributeValue(clazz,element,obj);return obj;} catch (Exception e) {e.printStackTrace();return null;}}private  Element getElement(String id) throws DocumentException {SAXReader saxReader = new SAXReader();Document document = saxReader.read("src/myconfig.xml");//精确定位到id属性值为传入字符串的bean元素return (Element) document.selectSingleNode("//bean[@id='" + id + "']");}private void setAttributeValue(Class<?> clazz, Element element,Object obj) throws IntrospectionException, IllegalAccessException, InvocationTargetException {Element subElement = element.element("property");//使用set方法赋值if (subElement != null) {String name = subElement.attributeValue("name");String valueStr = subElement.attributeValue("value");//创建属性描述器PropertyDescriptor descriptor = new PropertyDescriptor(name, clazz);//获取该属性的修饰符String s = descriptor.getPropertyType().getName();//获得写方法Method writeMethod = descriptor.getWriteMethod();//调用写方法Object value = null;if (s.equalsIgnoreCase("int")){value = Integer.parseInt(valueStr);}else if (s.equalsIgnoreCase("long")){value = Long.parseLong(valueStr);}else if (s.equalsIgnoreCase("short")){value = Short.parseShort(valueStr);}else if (s.equalsIgnoreCase("double")){value = Double.parseDouble(valueStr);}else if (s.equalsIgnoreCase("float")){value = Float.parseFloat(valueStr);}else if (s.equalsIgnoreCase("byte")) {value = Byte.valueOf(valueStr);}else{value = valueStr;}writeMethod.invoke(obj, value);}}
}