邮递员304未修改错误，弹簧支架api

Question

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我试图将POST方法发送到Spring rest api，但它始终显示304错误。有人知道什么可能导致此问题吗？ 谢谢

Client Controller.java（弹簧控制器）

   /* change client ip and client port. if change successful, save the settings to the dabase */
        @RequestMapping(value = "/clients/setConfiguration/{id}", method = RequestMethod.POST)
        public ResponseEntity<?> setConfiguration(@PathVariable Long id, @RequestBody ClientConfigDTO clientConfigDTO) {

            System.out.println("POST: ClientController.setConfiguration for client " + id);

            HttpStatus result = clientService.setConfiguration(id, clientConfigDTO);

            return new ResponseEntity<>(result);

        }

ClientConfigDto.java

 package at.fhwn.ma.serverapp.dto;

    public class ClientConfigDTO {

        private String ip;
        private String port;

        public ClientConfigDTO() {}

        public ClientConfigDTO(String ip, String port) {
            this.ip=ip;
            this.port=port;
        }

        public String getIp() {
            return ip;
        }
        public void setIp(String ip) {
            this.ip = ip;
        }
        public String getPort() {
            return port;
        }
        public void setPort(String port) {
            this.port = port;
        }

    }