Spring Boot REST endpoint connection not being released - rest

Question

I have created Spring boot (2.1.4.RELEASE) REST endpoint to GET some data from the server. When I call this endpoint from the browser, I see the JSON in the browser window but I notice that the the spinner in fav icon is going on for 60 seconds. When i look at the network tab, I never see the response section for the request. After 60 seconds, it says that it failed. When I walk through the code in debugger, I see that data is being returned from the controller and when I 'play' the rest of the stack everything completes (thread that is being assigned to serve the request) I am kind of puzzled what's causing this behavior.
#GetMapping(path="/recipes")
public ResponseEntity<Collection<HpManifest>> getRecipes() {
ResponseEntity<Collection<HpManifest>> response = hpService.getRecipes();
return response;
}
public ResponseEntity<Collection<HpManifest>> getRecipes() {
logger.info("Retrieving recipes from");
UriComponentsBuilder builder =
UriComponentsBuilder.fromHttpUrl(endpointManifests)
.queryParam("type", HpManifestType.RECIPE.getType());
logger.info("REST endpoint: " + builder.toUriString());
ResponseEntity<Collection<HpManifest>> recipes = restTemplate.exchange(
builder.toUriString(),
HttpMethod.GET, null, new ParameterizedTypeReference<Collection<HpManifest>>() {});
logger.info("recipes are:");
recipes.getBody().forEach(r -> logger.info(r.toString()));
return recipes;
}

Answer 1

I ran into a similar issue just the other day. In my case it turned out to be that recipes (returned from the restTemplate.exchange method) contained a Transfer-Encoding: chunked in the headers and then when you return recipes, your spring framework is probably also including a Content-Length header. The combination of these two headers in a response to a browser can cause issues because the browser thinks it's getting chunked data back, but in reality it is not. I suggest making a new ResponseEntity from your recipes variable along the lines of:
return ResponseEntity.status(recipes.getStatusCode()).body(response.getBody());
Alternatively you could maybe force your spring framework to return chunked data, but I think that is not the right way to go.