XML学习总结——SAXReader解析xml文件，实现反射 代码实例

<?xml version="1.0" encoding="UTF-8" ?> 
- <web-app xmlns="http://www.example.org/web-app_2_5" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.example.org/web-app_2_5 web-app_2_5.xsd" version="2.5">
- <servlet>
  <servlet-name>MyServlet1</servlet-name> 
  <servlet-class>cn.itheima.web.servlet1.MyServlet1</servlet-class> 
  </servlet>
- <servlet-mapping>
  <servlet-name>MyServlet1</servlet-name> 
  <url-pattern>/myServlet1</url-pattern> 
  </servlet-mapping>
- <servlet>
  <servlet-name>MyServlet2</servlet-name> 
  <servlet-class>cn.itheima.web.servlet1.MyServlet2</servlet-class> 
  </servlet>
- <servlet-mapping>
  <servlet-name>MyServlet2</servlet-name> 
  <url-pattern>/myServlet2</url-pattern> 
  </servlet-mapping>
  </web-app>

public interface IMyServlet {
  public void init();
  public void service();
  public void destory();
}

public class MyServlet1 implements IMyServlet{
  @Override
  public void init() {
    System.out.println("MyServlet1诞生了……");
  }
  @Override
  public void service() {
    System.out.println("MyServlet1开始服务了……");
  }
  @Override
  public void destory() {
    System.out.println("MyServlet1销毁了……");
  }
}

public class MyServlet2 implements IMyServlet{
  @Override
  public void init() {
    System.out.println("MyServlet2诞生了……");
  }
  @Override
  public void service() {
    System.out.println("MyServlet2开始服务了……");
  }
  @Override
  public void destory() {
    System.out.println("MyServlet2销毁了……");
  }
}

@Test
  public void testMyServlet(){
    try {
      //1.创建解析器对象
      SAXReader saxReader = new SAXReader();
      //2.使用解析器加载web.xml文件得到document对象
      Document document = saxReader.read("src/cn/itheima/web/servlet1/web.xml");
      //3.获取根元素节点
      Element rootElement = document.getRootElement();
      //4.根据元素名称获取子元素节点
      Element servletElement = rootElement.element("servlet");
      //5.根据元素名称获取servlet-class的文本节点
      String servletClass = servletElement.element("servlet-class").getText();
      //System.out.println(servletClass);
      //6.通过类全名获取字节码文件
      Class clazz = Class.forName(servletClass);
      //7.创建实例对象
      MyServlet1 my = (MyServlet1) clazz.newInstance();
      //8.调用实例对象里面的方法
      my.init();
      my.service();
      my.destory();
    } catch (Exception e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }