How to mimic curl REST call with Spring's RestTemplate? - spring

Question

Have an external Restful Web Service which takes in JSON payloads if its is more than one input but if its a single input it just needs the value.
For example, for multiple inputs, this works:
curl -H "Content-Type: application/json" -X POST -d '{ "amount": 10000, "interestRate": ".28", "term": "12", "state": "Georgia"}' http://localhost:8080/webservices/REST/sample/loan
Returns:
Approved
For single inputs:
curl -H "Content-Type: application/json" -X POST -d "18" http://localhost:8080/webservices/REST/sample/age
Returns:
Approved
Using Spring Boot, tried to create a JUnit test, in order, to see if I can post to this external service using Spring's RestTemplate API.
public void RestWebServiceTest {
private RestTemplate restTemplate;
private HttpHeaders headers;
#Before
public void setup() {
restTemplate = new RestTemplate();
headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
}
#Test
public void validLoan() {
final String uri = "http://localhost:8080/webservices/REST/sample/Loan";
Map<String, String> input = new HashMap<>();
input.put("amount", "10000");
input.put("interestRate", ".28");
input.put("term", "12");
input.put("state", "Georgia");
String result = restTemplate.postForObject(uri, input, String.class);
assertEquals("Approved", result);
}
#Test
public void validAge() {
final String uri = "http://localhost:8080/webservices/REST/sample/age";
Integer input = 18;
String result = restTemplate.postForObject(uri, input, String.class);
assertEquals("Approved", result);
}
#Test
public void validCountry() {
final String uri = "http://localhost:8080/webservices/REST/sample/country
String input = "US";
String result = restTemplate.postForObject(uri, input, String.class);
assertEquals("Approved", result);
}
}
All of these work except for the validCountry() test method:
org.springframework.web.client.HttpClientErrorException: 415 Unsupported Media Type
at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:91)
at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:641)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:597)
This is strange because this curl command works for the same call:
curl -H "Content-Type: application/json" -X POST -d 'US' http://localhost:8080/webservices/REST/sample/country
Returns:
Approved
Question(s):
How can one mimic the rest call for the country (see above curl command) inside the validCountry() test method?
Do I need to add or change a different value for HTTP Headers (inside setup() method)?
Don't understand that validAge works by using the Integer wrapper class but the String doesn't?
Is there a better way to do this using Spring's RestTemplate API?
Thank you for taking the time to read this...

Answer 1

You need to set the Content-Type to application/json. Content-Type has to be set in request. Below is the modified code to set the Content-Type
#Test
public void validCountry() {
final String uri = "http://localhost:8080/webservices/REST/sample/country";
String input = "US";
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<String> request = new HttpEntity<String>(input, headers);
String result = restTemplate.postForObject(uri, request, String.class);
assertEquals("Approved", result);
}
Here, HttpEntity is constructed with your input i.e "US" and with headers.
I think this answers you questions 1,2 and 4. But not 3.