含有过滤器的session小应用

带有过滤器的session小应用
一个JSP登录页面
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page import="com.mison.User"%>
<html>
  <head>
  
    
    <title>My JSP 'sessionLogin.jsp' starting page</title>

  </head>
  
  <body>
       <%
          String username=request.getParameter("username");
          String authority=request.getParameter("authority");
       
       %>
       
      <form action="MyLoginCheck">
         username1:<input type="text" name="username" value="<%=  null==username?"":username%>"><br>
         password:<input type="password" name="password" value=""><br>
         authority:
         <select name="authority">
             <option value="boss" <%=  "boss"==authority?"":"selected='selected'" %>>boss</option>
             <option value="user"  <%=  "user"==authority?"":"selected='selected'" %>>user</option>
         </select><br>
         <input type="submit" value="submit">
      </form>
  </body>
</html>



一个验证是否登录成功的Servlet类
package com.mison;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class MyLoginCheck extends HttpServlet {

	
	public void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		   User user=new User();
           HttpSession session =req.getSession();
           String username=req.getParameter("username");
           String password=req.getParameter("password");
           String authority=req.getParameter("authority");
           
           if("boss".equals(authority)){
        	   if("chenjing".equals(username)&&"chenjing".equals(password)){
        		     
        		     user.setName(username);
        		     user.setPassword(password);
        		     user.setAuthority(authority);
        		     
        		     
        		     session.setAttribute("user", user);
        		     
        		     req.getRequestDispatcher("index.jsp").forward(req, resp);
        		     
        	   }
        	   else{
        		   resp.sendRedirect("sessionLogin.jsp?username="+username+"&authority="+authority);
//        		   user.setName(username);
//            	   
//        		   user.setAuthority(authority);
//            	   
//            	   session.setAttribute("user", user);
//            	  
//            	   RequestDispatcher dp=req.getRequestDispatcher("sessionLogin.jsp");
//            	   
//            	   dp.forward(req, resp);
        	   }
        	   
           }
           else if("user".equals(authority)){
        	   if("chenfeng".equals(username)&&"chenfeng".equals(password)){
        		 
        		 user.setName(username);
      		     user.setPassword(password);
      		     user.setAuthority(authority);
      		     
      		     
      		     session.setAttribute("user", user);
        		 
      		     req.getRequestDispatcher("sessionout.jsp").forward(req, resp);
        	   }
        	   else{
        		   resp.sendRedirect("FilterTest.jsp?username="+username+"&authority="+authority);
//        		   user.setName(username);
//            	   
//        		   user.setAuthority(authority);
//            	   
//            	   session.setAttribute("user", user);
//            	  
//            	   RequestDispatcher dp=req.getRequestDispatcher("sessionLogin.jsp");
//            	   
//            	   dp.forward(req, resp);
        		   
        	   }
        	   
           }
           else{
        	   resp.sendRedirect("FilterTest.jsp?username="+username+"&authority="+authority);
           }
         
	
	}

}




重点中的重点:
package com.mison1;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class MyFilter implements Filter{

	public void destroy() {
		
		
	}

	public void doFilter(ServletRequest req, ServletResponse resp,
			FilterChain chain) throws IOException, ServletException {
		
		HttpServletRequest  request=(HttpServletRequest)req;
		String requestURL=request.getRequestURI();
		if(requestURL.endsWith("FilterTest.jsp")||requestURL.endsWith("MyLoginCheck")){
			 chain.doFilter(req, resp);
			 return;
		}
		HttpSession session=request.getSession();
		if(null==session.getAttribute("user")){
			((HttpServletResponse)resp).sendRedirect("FilterTest.jsp");
			return;
		}
		else{
			chain.doFilter(req, resp);
		}
	}

	public void init(FilterConfig arg0) throws ServletException {
		
		System.out.println("Filter start");
	}

}



一个基本用户和管理者可以操作的Query类
package com.mison;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyQueryServlet extends HttpServlet {

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

	   System.out.println("MyQueryServlet");
	}

}



一个只有管理者可以操作的Update类

package com.mison;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyUpdateServlet extends HttpServlet {

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

	        System.out.println("MyUpdateServlet");
	}

}



一个显示不同用户下不同页面效果的JSP
<%@ page language="java" import="com.mison.User" pageEncoding="UTF-8"%>

<html>
  <head>
    
    
    <title>My JSP 'index.jsp' starting page</title>
    
	

  </head>
  
  <body>
     <a href="MyQueryServlet">query</a>
        <%if(((User)session.getAttribute("user")).getAuthority().equals("boss")){%>
        <a href="MyUpdateServlet">update</a>
       
        <% }%>
  </body>
</html>



省略web.xml里面的配置