SSM框架项目的mvc拦截器

为了防止用户在不登录的情况下通过并接请求直接访问系统，我们需要通过session和拦截器来防止这样的情况。

拦截器的配置：

为拦截器建立一个包：interceptor，并在包里建立 LoginInterceptor 拦截器类

拦截器需要 implements HandlerInterceptor，并实现 HandlerInterceptor 的方法：

1/**
2 * 登录拦截器
3 */
4public class LoginInterceptor implements HandlerInterceptor {
5
6    @Override
7    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
8
9        HttpSession session = httpServletRequest.getSession();
10        if ( session.getAttribute("LOGIN_USER") != null ){
11            return true;
12        }else {
13            httpServletResponse.sendRedirect( httpServletRequest.getContextPath() + "/gradu/dologin");
14            return false;
15        }
16    }
17
18    @Override
19    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
20
21    }
22
23    @Override
24    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
25
26    }
27}

配置spring-mvc文件：

1<!--拦截器-->
2    <mvc:interceptors>
3        <mvc:interceptor>
4            <mvc:mapping path="/**" />
5            <mvc:exclude-mapping path="/gradu/dologin" />
6            <bean class="com.hwl.interceptor.LoginInterceptor"></bean>
7        </mvc:interceptor>
8    </mvc:interceptors>

注意：

<mvc:mapping path="/**"/> 是已经拦截了所有请求，包括登录，

如果后来想不拦截某个页面，就添加：<mvc:exclude-mapping path="/system/login" />

另外。记得登录时添加session。