spring boot 自己输出json数据

@RequestMapping("/json")public void json(HttpServletResponse response, Pager pager, TruckFee entity) throws IOException{    response.addHeader("Access-Control-Allow-Origin", "*");    response.setHeader("Content-Type", "application/json;charset=UTF-8");    PrintWriter write = response.getWriter();    write.write("{id:100}");    write.flush();}