springMVC 拦截器如何做登录检查及页面跳转

Question

一个非常简单的登录权限拦截器

问题一：登录页面的提交请求肯定是要过滤掉的，目前采用在xml里配置<mvc:mapping path="/supplier/*"/>来过滤，可不可以配置不拦截某种请求。如果是按目前这种配置需要拦截请求，当请求太多的时候那就太麻烦了。

问题二：我简单地在拦截器里判断session是否有值，如果有表示登录，如果没有则跳转登录页面。按我下面的做法是不行的，有没有正确而有效的方法。

问题三：如果大家能够给出在拦截器内跳转页面的方案，可我的login.jsp是放在WEB-INF下面的，通过ModelAndView跳转时，视图解析器会跳转到/WEB-INF/login.jsp下，那肯定是找不到页面的。但如果我放到此文件夹下，那浏览器又不能访问login.jsp页面了。

 

public class UserInterceptor implements HandlerInterceptor{

    @Override
    public void afterCompletion(HttpServletRequest request,
            HttpServletResponse response, Object obj, Exception err)
            throws Exception {
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response,
            Object obj, ModelAndView mav) throws Exception {
        response.sendRedirect("/login.jsp");
    }

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
            Object obj) throws Exception {
        String str = (String) request.getSession().getAttribute("isLogin");
        System.out.println("str=========>"+str);
        if(str!=null){
            return true;
        }
        return false;
    }
}

<!-- 自定义拦截链配置 -->
    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/supplier/*"/>
            <mvc:mapping path="/goods/*"/>
            <mvc:mapping path="/contact/*"/>
            <bean class="com.xiaoxing.shangjia.user.controller.UserInterceptor"></bean>
        </mvc:interceptor>
    </mvc:interceptors>

Answer 1

如果是判断是否登录。建议使用filter [code="java"]package com.ccsu.common.filter;

import com.ccsu.common.constants.SessionConstants;
import com.ccsu.entity.userSystem.User;
import com.ccsu.util.userSystem.ProsReader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpStatus;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

/**

• Created with IntelliJ IDEA.
• User: Ambitor springMVC拦截器 判断session中用户是否过期
• Date: 13-6-27
• Time: 下午7:31
• To change this template use File | Settings | File Templates. *
• @author 罗涛 */

public class SystemFilter implements Filter {

Logger logger = LoggerFactory.getLogger(SystemFilter.class);


@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
    if (!(servletRequest instanceof HttpServletRequest) || !(servletResponse instanceof HttpServletResponse)) {
        throw new ServletException("OncePerRequestFilter just supports HTTP requests");
    }
    HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
    HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
    HttpSession session = httpRequest.getSession(true);

    StringBuffer url = httpRequest.getRequestURL();
    String[] strs = ProsReader.getString("INDICATION_APP_NAME").split("\\|");
    if (strs != null && strs.length > 0) {
        for (String str : strs) {
            if (url.indexOf(str) >= 0) {
                filterChain.doFilter(servletRequest, servletResponse);
                return;
            }
        }
    }
    Object object = session.getAttribute(SessionConstants.SESSION_USER);
    User user = object == null ? null : (User) object;
    if (user == null) {
        boolean isAjaxRequest = isAjaxRequest(httpRequest);
        if (isAjaxRequest) {
            httpResponse.setCharacterEncoding("UTF-8");
            httpResponse.sendError(HttpStatus.UNAUTHORIZED.value(),
                    "您已经太长时间没有操作,请刷新页面");
        }
        httpResponse.sendRedirect("/page/login/user_login");
        return;
    }
    filterChain.doFilter(servletRequest, servletResponse);
    return;
}

/**
 * 判断是否为Ajax请求
 *
 * @param request HttpServletRequest
 * @return 是true, 否false
 */
public static boolean isAjaxRequest(HttpServletRequest request) {
    return request.getRequestURI().startsWith("/api");

// String requestType = request.getHeader("X-Requested-With");
// return requestType != null && requestType.equals("XMLHttpRequest");
}

@Override
public void init(FilterConfig filterConfig) throws ServletException {
        /*如果需要注入，请取消注释*/

// ServletContext servletContext = filterConfig.getServletContext();
// WebApplicationContext applicationContext = (WebApplicationContext) servletContext.
// getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
// if (null == topConstantsImpl) {
// //从Spring AC 中加载app configuration对象
// topConstantsImpl = applicationContext.getBean(TopConstantsImpl.class);
// }
}

@Override
public void destroy() {
    //To change body of implemented methods use File | Settings | File Templates.
}

}
[/code]

[code="java"] <!--<!– 判断用户session 是否过期，如果过期，让用户重新登录–>-->
<!---->
<!--SystemFilter-->
<!--com.yitaosoft.common.filter.SystemFilter-->
<!---->
<!---->
<!--SystemFilter-->
<!--/*-->
<!---->[/code]