springmvc添加拦截器

<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/**" />
        <mvc:exclude-mapping path="/sysFile/**" />
        <mvc:exclude-mapping path="/users/loginUser.do" />
        <bean class="com.test.interceptor.UserInterceptor" />
     </mvc:interceptor>
</mvc:interceptors>

public class UserInterceptor extends HandlerInterceptorAdapter{
    
    @Autowired
    private IUsersService usersService;
    
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        
        try {
            request.setCharacterEncoding("UTF-8");
        } catch (UnsupportedEncodingException e) {
            return false;
        }
　　　　　//获取前台传入userId
        String userId = request.getParameter("userId");
　　　　 //获取前台传入的 token
        String token = request.getParameter("token");
　　　　 //根据userId从数据库获取user信息
        UsersVo usersVo = usersService.findUserById(userId);
        if(usersVo == null){
            return false;//拦截
        }
        
　　　　 //判断前台传入的token 与 数据获取的token做比较
        if(usersVo.getToken() == null || "".equals(usersVo.getToken()) || !usersVo.getToken().equals(token)){
            return false;//拦截
        }
　　　　　//不拦截
        return true;
    }
}