拦截器preHandle直接返回状态和JSON

 @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
        System.out.println("-----------------------进入拦截器-------------------------");
        //每次都会先发一个不带参数的OPTIONS请求，若此请求失败则不会发起正式请求，所以要过滤掉OPTIONS请求
        if (HttpMethod.OPTIONS.toString().equals(request.getmethod())) {
            System.out.println("OPTIONS请求，放行");
            return true;
        }
        try {
            String token=request.getHeader("Authorization");
            //如果验证token失败，并且方法注明了Authorization，返回401错误
            if (token == null) {

                //设置response状态
                response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
                response.setCharacterEncoding("UTF-8");
                response.setContentType("application/json; charset=utf-8");

                //返回的数据
                JSONObject res = new JSONObject();
                res.put("status","-1");
                res.put("msg","need login");
                PrintWriter out = null ;
                out = response.getWriter();
                out.write(res.toString());
                out.flush();
                out.close();


                return false;
            }
        }catch (Exception e){
            return false;
        }

        return true;
    }