1.环境搭建

<dependency>
    <groupId>org.dom4j</groupId>
    <artifactId>dom4j</artifactId>
    <version>2.1.1</version>
</dependency>

<dependency>
    <groupId>jaxen</groupId>
    <artifactId>jaxen</artifactId>
    <version>1.1.6</version>
</dependency>

2.目录结构

3.模拟bean配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<beans>
    <bean id="user" class="spring.ioc3.entity.Student">
        <property name="name" value="xiaoming"/>
        <property name="address" value="xiaoyingdajie"/>
    </bean>
</beans>

4.Application文件

package spring.ioc3.context;

public interface Application {
    public Object getBean(String beanId);
}

5.ClassPathApplication文件

package spring.ioc3.context;

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

import java.io.File;
import java.lang.reflect.Method;
import java.net.URLDecoder;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ClassPathApplication implements Application {
    Map beanAll = new HashMap();

    public ClassPathApplication() {
        try {
            String filePath = this.getClass().getResource("/applicationContext1.xml").getPath();
            filePath = new URLDecoder().decode(filePath, "UTF-8");
            SAXReader reader = new SAXReader();
            Document d = reader.read(new File(filePath));
            List<Node> nodes = d.getRootElement().selectNodes("bean");
            for (Node node : nodes) {
                Element ele = (Element) node;
                String id = ele.attributeValue("id");
                String className = ele.attributeValue("class");
                Class c = Class.forName(className);
                Object obj = c.newInstance();
                List<Node> properties = node.selectNodes("property");
                for (Node p : properties) {
                    Element e = (Element) p;
                    String name = e.attributeValue("name");
                    String value = e.attributeValue("value");
                    String methodName = "set" + name.substring(0, 1).toUpperCase() + name.substring(1);
                    Method method = c.getMethod(methodName, String.class);
                    method.invoke(obj, value);
                }
                beanAll.put(id, obj);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public Object getBean(String beanId) {
        return beanAll.get(beanId);
    }

}

6.XMLApplication文件

package spring.ioc3;

import spring.ioc3.context.Application;
import spring.ioc3.context.ClassPathApplication;
import spring.ioc3.entity.Student;

public class XMLApplication {
    public static void main(String[] args) {
        Application application = new ClassPathApplication();
        Student stu = (Student) application.getBean("user");
        System.out.println(stu.getAddress());
        System.out.println(stu.getName());
    }
}

实例化后输出：