RestTemplate should support Void response types [SPR-8572]

[spring-projects-issues]

Brad Cupit opened SPR-8572 and commented

when calling RestTemplate.exchange() I should be able to use a Void response type. Example (notice the last parameter):

restTemplate.exchange(webServiceUrl, HttpMethod.DELETE, null, Void.class);

The Void class implies no return entity and reads a little better than null for the response type.

The fix should be trivial. In RestTemplate.ResponseEntityResponseExtractor's constructor, just change this line:
if (responseType != null)
to this:
if (responseType != null && responseType != Void.class)

---

Affects: 3.0.5

Referenced from: commits c472a16

[spring-projects-issues]

Brad Cupit commented

whoops, here's the same report with formatting:

when calling RestTemplate.exchange() I should be able to use a Void response type. Example (notice the last parameter):

restTemplate.exchange(webServiceUrl, HttpMethod.DELETE, null, Void.class);

The Void class implies no return entity and reads a little better than null for the response type.

The fix should be trivial. In RestTemplate.ResponseEntityResponseExtractor's constructor, just change this line:
if (responseType != null)
to this:
if (responseType != null && responseType != Void.class)

[spring-projects-issues]

Brad Cupit commented

This has an impact when using the return value. The proposed change would look like this:

ResponseEntity<Void> response = restTemplate.exchange(webServiceUrl, HttpMethod.DELETE,
                                                      null, Void.class);
Void body = response.getBody();

vs. the current code which looks like this:

ResponseEntity<Object> response = restTemplate.exchange(webServiceUrl, HttpMethod.DELETE,
                                                        null, null);
Object body = response.getBody();

The first example is more obvious that you can't get the body since it's Void.