session过滤器,求人不如求已,动手写个过滤器,record一下,免得以后到处找

1.SessionFilter类,实现了Filter接口

package filters;

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.HttpSession;


public class SessionFilter implements Filter ...{

    public void destroy() ...{
        // TODO Auto-generated method stub
//          System.out.println("** 过滤器销毁...") ;
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException ...{
        // TODO Auto-generated method stub
        HttpServletRequest req = (HttpServletRequest)request ;

           HttpSession session = req.getSession();
           

//           if(session.getAttribute("loginname")!=null){ //暂时只过滤登陆名
//               chain.doFilter(request,response);
//           }else{
//            // 通过requestDispatcher跳转到登陆页
//               request.getRequestDispatcher("login.jsp").forward(request,response);
//           }
           
           try
           ...{
              request.setCharacterEncoding("GBK");
              String url= req.getRequestURI();
              System.out.println(url);

             
                  if(session.getAttribute("loginname")!=null)...{ //暂时只过滤登陆名
                   chain.doFilter(request,response);
               }else...{
                   if(url.indexOf("login.jsp")!=-1 || url.indexOf("login.do")!=-1)...{
                       chain.doFilter(request,response);
                   }else...{
            // 通过requestDispatcher跳转到登陆页
                       request.getRequestDispatcher("login.jsp").forward(request,response);
               }
               }
           }
           catch (Exception ex)
           ...{
               ex.printStackTrace();
           }

    }

    public void init(FilterConfig config) throws ServletException ...{
        // TODO Auto-generated method stub
//         System.out.println("** 过滤器初始化...") ;
    }

}

2.配置web.xml,说明哪些文件需要过滤

        <filter-name>SessionFilter</filter-name>
        <filter-class>filters.SessionFilter</filter-class>
      </filter>
      <!-- ... -->
      <filter-mapping>
        <filter-name>SessionFilter</filter-name>
        <url-pattern>/manager/*</url-pattern>
      </filter-mapping>

搞定,洗个澡睡觉,明天开始写其他功能.