有两种方法-
首先，您所做的只是将这些参数与url一起追加，而不需要在正文中给予它们。url将类似于- baseurl+/requestotp？idNumber=123&applicationId=123

@RequestMapping(value="/requestotp",method = RequestMethod.POST) 
    public String requestOTP( @RequestParam(value="idNumber") String idNumber , @RequestParam(value="applicationId") String applicationId) {
        return customerService.requestOTP(idNumber, applicationId);

第二，您可以按如下方式使用Map

@RequestMapping(value="/requestotp",method = RequestMethod.POST) 
    public String requestOTP( @RequestBody Map<String,Object> body) {
        return customerService.requestOTP(body.get("idNumber").toString(), body.get("applicationId").toString());

我已经修改了你的代码，请检查一下

DTO类别

public class DTO1 {

private String idNumber;
private String applicationId;

public String getIdNumber() {
    return idNumber;
}

public void setIdNumber(String idNumber) {
    this.idNumber = idNumber;
}

public String getApplicationId() {
    return applicationId;
}

public void setApplicationId(String applicationId) {
    this.applicationId = applicationId;
}

}
Rest控制器方法

@RequestMapping(value="/requestotp",method = RequestMethod.POST) 
public String requestOTP( @RequestBody DTO1 dto){
    System.out.println(dto.getApplicationId()+"  (------)  "+dto.getIdNumber());
    return "";
}

请求类型--应用程序/json {“标识号”：“345”，“应用程序ID”：“64536”}
或

@RequestMapping(value="/requestotp",method = RequestMethod.POST) 
public String requestOTP( @RequestBody String dto){
    System.out.println(dto);
    return "";
}