How to send HTTP OPTIONS request with body using Spring rest template? - spring

Question

I am trying to call a RESTfull web service resource, this resource is provided by a third party, the resource is exposed with OPTIONS http verb.
To integrate with the service, I should send a request with a specific body, which identities by a provider, but when I did that I got a bad request. After that I trace my code then I recognized that the body of the request is ignored by rest template based on the below code:
if ("POST".equals(httpMethod) || "PUT".equals(httpMethod) ||
"PATCH".equals(httpMethod) || "DELETE".equals(httpMethod)) {
connection.setDoOutput(true);
}
else {
connection.setDoOutput(false);
}
my question, is there a standard way to override this behavior or I should use another tool?

Answer 1

The code you've pasted is from
SimpleClientHttpRequestFactory.prepareConnection(HttpURLConnection connection, String httpMethod)
I know because I've debugged that code few hours ago.
I had to do a HTTP GET with body using restTemplate. So I've extend SimpleClientHttpRequestFactory, override prepareConnection and create a new RestTemplate using the new factory.
public class SimpleClientHttpRequestWithGetBodyFactory extends SimpleClientHttpRequestFactory {
#Override
protected void prepareConnection(HttpURLConnection connection, String httpMethod) throws IOException {
super.prepareConnection(connection, httpMethod);
if ("GET".equals(httpMethod)) {
connection.setDoOutput(true);
}
}
}
Create a new RestTemplate based on this factory
new RestTemplate(new SimpleClientHttpRequestWithGetBodyFactory());
A test to prove the solution is working using spring boot (#RunWith(SpringRunner.class)
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT))
public class TestRestTemplateTests extends AbstractIntegrationTests {
#Test
public void testMethod() {
RestTemplate restTemplate = new RestTemplate(new SimpleClientHttpRequestWithBodyForGetFactory());
HttpEntity<String> requestEntity = new HttpEntity<>("expected body");
ResponseEntity<String> responseEntity = restTemplate.exchange("http://localhost:18181/test", HttpMethod.GET, requestEntity, String.class);
assertThat(responseEntity.getBody()).isEqualTo(requestEntity.getBody());
}
#Controller("/test")
static class TestController {
#RequestMapping
public #ResponseBody String testMethod(HttpServletRequest request) throws IOException {
return request.getReader().readLine();
}
}
}