过滤器（filter）实现用户登录拦截

过滤器（filter）实现用户登录拦截

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.

蕃薯耀 2015年8月25日 16:20:47 星期二

http://fanshuyao.iteye.com/

一、增加一个Java类，实现filter接口

public class UserFilter implements Filter {

	@Override
	public void destroy() {
		System.out.println("userFilter destroy()");

	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest req = (HttpServletRequest)request;
		HttpServletResponse res = (HttpServletResponse) response;
		HttpSession session = req.getSession();
		//User user = (User) session.getAttribute(Conf.SESSION_USER);
		String user = (String) request.getAttribute("user");
		if (user != null) {
			chain.doFilter(request, response);
		} else {
			session.setAttribute("redirect_url", req.getRequestURL().toString());
			//System.out.println("req.getRequestURL().toString()="+req.getRequestURL().toString());
			res.sendRedirect(req.getContextPath() + "/login?redirect_url="+URLEncoder.encode(req.getRequestURL().append("?").append(req.getQueryString()).toString(), "utf-8"));
		}
	}

	@Override
	public void init(FilterConfig arg0) throws ServletException {
		System.out.println("userFilter init()");

	}

二、配置web.xml文件

<filter>
   <filter-name>userFilter</filter-name>
   <filter-class>com.spring.filter.UserFilter</filter-class>
  </filter>

  <filter-mapping>
   <filter-name>userFilter</filter-name>
   <url-pattern>/user/*</url-pattern>
  </filter-mapping>

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.

蕃薯耀 2015年8月25日 16:20:47 星期二

http://fanshuyao.iteye.com/