Spring RestTemplate : BadRequest 400,null. while calling Get Request

Question

I am trying to call get request using RestTemplate. I tried like below But I am getting error HttpClientErrorException$BadRequest: 400 null.

Can any one tell me what I am doing wrong in calling Get Request with parameters?

@GetMapping("/getDepartmentInstitute")
public Integer getDeptInstByUserIDAndInstId(@RequestParam Integer nUserId,
                                            @RequestParam Integer  nDeptInst) {
return permissionsService.findDeptInstByUserIdAndInstId(nUserId,nDeptInst );        
}

I tried like this

public Integer findAlertDetails(Integer nUserId, Integer nInstId) {                 

    String uri="http://localhost:8064/spacestudy/" +instituteIdentifier +"/communication/alertmanagement/getDepartmentInstitute?nUserId="+ nUserId+"&nInstId="+nInstId+"";

        RestTemplate restTemplate = new RestTemplate();

       Integer nInstTo=restTemplate.getForObject(uri,Integer.class,nUserId,nInstId);

            System.out.println(nInstTo);    

        return nInstTo;
    }

Answer 1

restTemplate.getForObject(String url, Class responseType, Object... uriVariables) is supposed to deal with uri variables like {myVar} in your String url.

If you want to set query parameters, consider using the UriComponentsBuilder.

URI uri = UriComponentsBuilder.fromHttpUrl("http://localhost:8064/spacestudy/" +instituteIdentifier +"/communication/alertmanagement/getDepartmentInstitute")
              .queryParam("nUserId", nUserId)
              .queryParam("nDeptInst", nInstId)
              .build().toUri();

Integer nInstTo = restTemplate.getForObject(uri,Integer.class);

Or you can set them manually like :

String uri = "http://localhost:8064/spacestudy/" +instituteIdentifier +"/communication/alertmanagement/getDepartmentInstitute"
                   + "?nUserId=" + nUserId + "&nDeptInst=" + nInstId;

I prefer the UriComponentsBuilder solution.