GET.java

public void findUserById() 
{
        String username = "chathuranga";
        String password = "123";
        Integer userId = 1;

        String url = "http://localhost:" + port + "/users/" + userId;

        //setting up the HTTP Basic Authentication header value
        String authorizationHeader = "Basic " + DatatypeConverter.printBase64Binary((username + ":" + password).getBytes());

        HttpHeaders requestHeaders = new HttpHeaders();
        //set up HTTP Basic Authentication Header
        requestHeaders.add("Authorization", authorizationHeader);
        requestHeaders.add("Accept", MediaType.APPLICATION_JSON_VALUE);

        //request entity is created with request headers
        HttpEntity<AddUserRequest> requestEntity = new HttpEntity<>(requestHeaders);

        //adding the query params to the URL
        UriComponentsBuilder uriBuilder = UriComponentsBuilder.fromHttpUrl(url)
                .queryParam("name", "chathuranga")
                .queryParam("email", "chathuranga.t@gmail.com");

        ResponseEntity<FindUserResponse> responseEntity = restTemplate.exchange(
                uriBuilder.toUriString(),
                HttpMethod.GET,
                requestEntity,
                FindUserResponse.class
        );

        if (responseEntity.getStatusCode() == HttpStatus.OK) {
            System.out.println("response received");
            System.out.println(responseEntity.getBody());
        } else {
            System.out.println("error occurred");
            System.out.println(responseEntity.getStatusCode());
        }
}