判断用户是否登录以及对编码格式进行过滤

package com.bgiseq.util;

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;

public class EncodeFilter implements Filter {

    public void destroy() {
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        // 将服务器的响应编码格式设置为UTF-8
        response.setContentType("text/html;charset=utf-8");
        // 浏览器请求服务器过滤乱码
        request.setCharacterEncoding("utf-8");
        chain.doFilter(request, response);
        
    }

    public void init(FilterConfig arg0) throws ServletException {

    }

}

<!-- 过滤编码 -->
    <filter>
        <filter-name>EncodeFilter</filter-name>
        <filter-class>com.bgiseq.util.EncodeFilter</filter-class>
    </filter>
    
    
    <filter-mapping>
        <filter-name>EncodeFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

package com.bgiseq.util;

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 UserIslogin implements Filter{

    @Override
    public void destroy() {}

    @Override
    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)
            throws IOException, ServletException {
        // 获得在下面代码中要用的request,response,session对象
        HttpServletRequest    request=(HttpServletRequest) req;  
        HttpServletResponse response = (HttpServletResponse) resp;
        HttpSession session = request.getSession();
        // 从session里登录信息
        String username= (String) session.getAttribute("Username");
        
        // 获得用户请求的URI
        String path =  request.getRequestURI();
        /*if(path.indexOf("css")!=-1||path.indexOf("images")!=-1||path.indexOf("jquery")!=-1||path.indexOf("script")!=-1||path.indexOf("all")!=-1||path.indexOf("loginUser")!=-1){
            chain.doFilter(req, resp);
        }
        */
        // 登陆页面无需过滤
        if(path.indexOf("/login.jsp") > -1) {
         chain.doFilter(request, response);
          return;
        }
        // 判断如果没有取到员工信息,就跳转到登陆页面
        if (username == null || "".equals(username)) {
             response.sendRedirect("/BGISEQ2/views/jsp/login/login.jsp");
        }else{
            // 已经登陆,继续此次请求
              chain.doFilter(req, resp);
        }
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {}


    
}

<!-- 判断用户是否登录 -->
    <filter>
        <filter-name>UserIslogin</filter-name>
        <filter-class>com.bgiseq.util.UserIslogin</filter-class>
    </filter>
    
    <filter-mapping>
        <filter-name>UserIslogin</filter-name>
        <url-pattern>/views/jsp/*</url-pattern>
    </filter-mapping>