过滤器过滤一个包内所有servlet

过滤器过滤一个包内所有servlet，先看下文件的目录结构:

我们要做的就是用MyFirstFilter过滤servlet包内的所有servlet即DisplayHeader、HelloServlet、SecondServlet。
主要就是两个注意事项:
1:

package servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class HelloServlet
 */
@WebServlet("/servlet/HelloServlet")
public class HelloServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public HelloServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub

//      String msg = request.getInputStream().toString();
//      response.getWriter().println("????????");
        response.getWriter().println(request.getAttribute("ServletPath"));
        response.getWriter().println("公司的分公司");
//      request.setAttribute("name", "????????HelloServlet?????marhong");
//      request.getRequestDispatcher("/SecondServlet").forward(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

这里一定要注意就是那个注释部分:

它原来的值是:@WebServlet(“/HelloServlet”),一定要改成上图所示的才可以

2.就是web.xml了,代码如下所示:

  
  
       
    MyFirstFilter
    com.util.MyFirstFilter
    
    encoding
    GBK
    
    
    secondAttribute
    filterConfig的第二个参数
    
    
    
    MyFirstFilter
    /servlet/*
   /checkIn.jsp
    
    
       
    HelloServlet  
      
    servlet.HelloServlet  
    
    
    HelloServlet  
      
    /SummerTest/servlet/HelloServlet  
      


    

    SecondServlet
    servlet.SecondServlet
    
       
    SecondServlet  
      
    /SummerTest/servlet/SecondServlet  

     
   
    
  DisplayHeader  
    
  servlet.DisplayHeader  
  
  
  DisplayHeader  
    
  /SummerTest/servlet/DisplayHeader  
 

注意这两个地方应该就可以达到目的了。