过滤器（filter）实现用户登录拦截

过滤器（filter）实现用户登录拦截

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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/