Spring MVC 拦截器实现

public SessionInterceptor() {
    // TODO Auto-generated constructor stub
}

private List<String> excludedUrls;

//通过属性注册不需要过滤的url list
public void setExcludedUrls(List<String> excludedUrls) {
    this.excludedUrls = excludedUrls;
}

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
    throws Exception {

    String requestUrl = request.getRequestURI();
    //排除不需要过滤的URL
    for(String url:excludedUrls) {
        if(requestUrl.endsWith(url)) {
            return true;
        }
    }
    //获取当前的会话session
    HttpSession session = request.getSession();
    if(session.getAttribute("userid") == null) {
        //若登录session过期或不存在就跳转到login页面
        request.getRequestDispatcher("/login.jsp").forward(request, response);
        return false;
    }
    return true;
}

}
springmvc-servlet.xml 拦截器注册

<mvc:interceptors>
<mvc:interceptor>