A very simple login permission interceptor, the specific code is as follows:
The following code is the code that inherits OncePerRequestFilter to implement login filtering:
/** * * @author geoin * @date 2012-4-10 2:37:38 pm */ package com.test.spring.filter; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.FilterChain; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.filter.OncePerRequestFilter; /** * Login filter* * @author geoin * @date 2012-4-10 2:37:38 pm */ public class SessionFilter extends OncePerRequestFilter { /* * (non-Javadoc) * * @see * org.springframework.web.filter.OncePerRequestFilter#doFilterInternal( * javax.servlet.http.HttpServletRequest, * javax.servlet.http.HttpServletResponse, javax.servlet.FilterChain) */ @Override protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException { // But filtered uri String[] notFilter = new String[] { "login.html", "index.html" }; // Requested uri String uri = request.getRequestURI(); // Filter if (uri.indexOf("background") != -1) { // Whether to filter boolean doFilter = true; for (String s : notFilter) { if (uri.indexOf(s) != -1) { // If uri contains unfiltered uri, doFilter = false; break; } } if (doFilter) { // Perform filtering// Get login's entity from session Object obj = request.getSession().getAttribute("loginedUser"); if (null == obj) { // If the login entity does not exist in the session, a pop-up box prompts to log in again// Set the character set of request and response to prevent garbled request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); PrintWriter out = response.getWriter(); String loginPage = "...."; StringBuilder builder = new StringBuilder(); builder.append("<script type=/"text/javascript/">"); builder.append("alert('The web page expires, please log in again!');"); builder.append("window.top.location.href='"); builder.append(loginPage); builder.append("';"); builder.append("</script>"); out.print(builder.toString()); } else { // If the login entity exists in the session, continue filterChain.doFilter(request, response); } } else { // If filtering is not performed, continue filterChain.doFilter(request, response); } } else { // If the uri does not contain background, continue filterChain.doFilter(request, response); } } } After writing the filter, you need to configure it in web.xml:
<filter> <filter-name>sessionFilter</filter-name> <filter-class>com.test.spring.filter.SessionFilter</filter-class> </filter> <filter-mapping> <filter-name>sessionFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
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