Java如何不用“return”返回数据

今天遇到了这样一个问题：拦截器中true为成功拦截，false为拦截失败那么怎么给前台用户提示配拦截呢？方法如下：

private void returnJson(HttpServletResponse response, String json) {
    response.setCharacterEncoding("UTF-8");
    response.setContentType("text/html; charset=utf-8");
    try (PrintWriter writer = response.getWriter()) {
        writer.print(json);
    } catch (IOException e) {
        log.error(e.getMessage());
    }
}