Spring RestTemplate Behavior when handling responses with a status of NO_CONTENT
One more way to solve this would be to make response entity as null as shown below.
ResponseEntity<?> response = restTemplate.exchange("http://localhost:8080/myapp/user/{userID}", HttpMethod.DELETE, requestEntity, null, userID);
If you still need response headers, try implementing the ResponseErrorHandler.
Here's a simple solution where you can set the default Content-Type for use if it is missing in the response. The Content-Type is added to the response header before it is handed back off to the preconfigured ResponseExtractor for extraction.
public class CustomRestTemplate extends RestTemplate {
private MediaType defaultResponseContentType;
public CustomRestTemplate() {
super();
}
public CustomRestTemplate(ClientHttpRequestFactory requestFactory) {
super(requestFactory);
}
public void setDefaultResponseContentType(String defaultResponseContentType) {
this.defaultResponseContentType = MediaType.parseMediaType(defaultResponseContentType);
}
@Override
protected <T> T doExecute(URI url, HttpMethod method, RequestCallback requestCallback, final ResponseExtractor<T> responseExtractor)
throws RestClientException {
return super.doExecute(url, method, requestCallback, new ResponseExtractor<T>() {
public T extractData(ClientHttpResponse response) throws IOException {
if (response.getHeaders().getContentType() == null && defaultResponseContentType != null) {
response.getHeaders().setContentType(defaultResponseContentType);
}
return responseExtractor.extractData(response);
}
});
}
}
I believe you should probably look at the ResponseExtractor interface & call execute on the RestTemplate providing your implementation of the extractor. To me it looks like a common requirement to do this so have logged this:
https://jira.springsource.org/browse/SPR-8016
Here's one I prepared earlier:
private class MyResponseExtractor extends HttpMessageConverterExtractor<MyEntity> {
public MyResponseExtractor (Class<MyEntity> responseType,
List<HttpMessageConverter<?>> messageConverters) {
super(responseType, messageConverters);
}
@Override
public MyEntity extractData(ClientHttpResponse response) throws IOException {
MyEntity result;
if (response.getStatusCode() == HttpStatus.OK) {
result = super.extractData(response);
} else {
result = null;
}
return result;
}
}
I've tested this & it seems to do what I want.
To create the instance of the ResponseExtractor I call the constructor & pass the converters from a RestTemplate instance that's been injected;
E.g.
ResponseExtractor<MyEntity> responseExtractor =
new MyResponseExtractor(MyEntity.class, restTemplate.getMessageConverters());
Then the call is:
MyEntity responseAsEntity =
restTemplate.execute(urlToCall, HttpMethod.GET, null, responseExtractor);
Your mileage may vary. ;-)