springmvc 登录拦截

港控/mmm° 2022-05-28 12:25 267阅读 0赞

用到拦截器： HandlerInterceptor

首先在spring-mvc.xml中配置

<mvc:interceptors>
            <mvc:interceptor>
                <mvc:mapping path="/**"/> 
                <bean class="com.car.Interceptor.LoginInterceptor"></bean> 
            </mvc:interceptor>
        </mvc:interceptors>

创建一个拦截器类实现HandlerInterceptor接口, 目前只需要在preHandle方法中实现代码即可 ,返回true表示可通过拦截器的请求

public class LoginInterceptor implements HandlerInterceptor { 
    
        @Override
        public boolean preHandle(HttpServletRequest httpServletRequest,
                                 HttpServletResponse httpServletResponse, Object o) throws Exception {
            //获取请求的url
            StringBuffer url = httpServletRequest.getRequestURL();
    
            //若是公开地址则允许通过
            if (url.toString().indexOf("login") >= 0){
                return true;
            }
    
            //获取session内容，若不存在身份信息则不允许访问
            UserInfo userInfo = (UserInfo) httpServletRequest.getSession().getAttribute("userInfo");
    
            if (userInfo != null){
                return true;
            }
            httpServletRequest.getRequestDispatcher("/admin/login")
                    .forward(httpServletRequest, httpServletResponse);
    
            return false;
        }
    
        @Override
        public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
    
        }
    
        @Override
        public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    
        }
    }

这样当用户登录成功后，session中存在userInfo这个值， 表示用户已经登录过可以访问自己主页的内容， 若session中不存在则重新回退到登录界面