Spring Boot REST endpoint not returning JSON - spring

I have the following code:
case class X(s: String)
#RequestMapping(path = Array("/tagReads"), produces = Array("application/json"))
def tagReads(#RequestParam(value = "tagId") tagId:String): X = {
val response = X("Hello")
println(response)
response
}
curl -H "Accept: application/json localhost:8080/tagReads?tagId="1234" results in exactly what I would expect being println-ed in the spring boot app, but the response I get is {}.
If I change the return to just "Hello" and the type to String then I get "Hello" returned when I curl.
I don't like that I'm getting empty JSON the rest of the time. I am using spring-boot-starter-web:2.1.6-RELEASEand this is all wrapped in an #RestController annotated class.
There is nothing useful logged to the Spring Boot application console.
I'm stuck - all the examples I've seen suggest this should 'just work' - so any help is much appreciated

In order to support Scala Case Classes serialization, try to add the jackson-module-scala as your dependency and register the Scala module with the Jackson ObjectMapper e.g.
val mapper = new ObjectMapper()
mapper.registerModule(DefaultScalaModule)

Related

Best Way to encode Fragment in URL - SpringBoot

I have a spring boot application where an endpoint responds with a url for the client to redirect to. This correct url looks something like:
https://checkout.stripe.com/c/pay/stuff#morestuff which is being properly logged below
Here is my spring boot code:
#PostMapping(path = "/create-checkout-session", produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<Void> createSubscription(#RequestParam String priceId) throws StripeException {
...
Session session = Session.create(params);
log.info("Redirecting with session {}", session.getUrl());
return ResponseEntity.status(HttpStatus.FOUND).location(URI.create(session.getUrl())).build();
}
However, when my client receives a response from my endpoint, the URL is truncated up to the # to something like:https://checkout.stripe.com/c/pay/stuff (removing the #morestuff).
I found this post about needing to encode the # and I was wondering what the best way to do this is?

How to migrate this mutlipart file upload to Spring Boot 2.4?

With Spring Boot 2.3 I was using the following Kotlin code
val mvcResultImage = this.mockMvc!!.perform(MockMvcRequestBuilders.multipart("/somepath)
.file("files[]", imageFile.getBytes())
.characterEncoding("UTF-8"))
.andReturn()
in an integration test for a controller with a function
#PostMapping(path = ["/somepath"],
consumes = [MediaType.MULTIPART_FORM_DATA_VALUE],
produces = [MediaType.APPLICATION_JSON_VALUE])
#ResponseBody
fun createFromBytes(#RequestParam("files[]") file: MultipartFile): ResponseEntity<Any> {
...
}
In 2.3 I was able to handle the request in the controller function whereas in 2.4 the controller function raises a org.springframework.web.multipart.support.MissingServletRequestPartException with the message Required request part 'files[]' is not present and causes HTTP response code 400.
I don't find anything in the migration guide and list of handled issues for this version change.
A rename to file in both controller and request doesn't help, I don't remember why I added [] in the code working with 2.3, but I think it was necessary to make it work.
I'm using Spring Boot through the maven parent mechanism with spring-boot-starter-parent:2.4.1.
This is a known issues in Spring Boot coming from Spring. It's fixed in Spring Boot 2.4.2. The linked issue contains a successfully tested workaround in case you're stuck with 2.4.1: Create MockMultipartFile with MockMultipartFile( String name, #Nullable String originalFilename, #Nullable String contentType, #Nullable byte[] content) (specification of originalFilename matters).

How do I unit test a Spring RestTemplate that takes a ResponseExtractor and RequestCallback?

I am developing in Groovy and I am trying to write a Spock unit test for the following use of Spring's RestTemplate...
Included are my request callback and response extractors, and my initialization class of the RestTemplate bean. I am using the ResponseExtractor to stream the response from GET myurl/ and copy it to a file. The RequestCallback is simply setting some headers on the request.
class RestTemplateConfig() {
#Bean(name = 'myRestTemplate')
RestTemplate getMyRestTemplate() {
RestTemplate restTemplate = new RestTemplateBuilder().build()
return restTemplate
}
}
class MyClass() {
#Autowired
#Qualifier('myRestTemplate')
RestTemplate restTemplate
File getFile() {
ResponseExtractor<Void> responseExtractor = { ClientHttpResponse response ->
// do something with the response
// in this case, the response is an input stream so we copy the input stream to a file
myFile = response.getBody() // roughly, in a psuedocode-ish way
return null
}
RequestCallback requestCallback = { ClientHttpRequest request ->
request.getHeaders().setAccept([MediaType.APPLICATION_JSON])
}
File myFile
// get my file data
restTemplate.execute('myurl/', HttpMethod.GET, requestCallback, responseExtractor)
return myFile
}
}
Spring framework docs for that particular execute(...) method: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/client/RestTemplate.html#execute-java.net.URI-org.springframework.http.HttpMethod-org.springframework.web.client.RequestCallback-org.springframework.web.client.ResponseExtractor-
How do I mock out what's happening in these closures? Specifically, I'm interested in mocking out my response extractor because my current test always returns myFile as null.
when:
// do stuff
then:
1 * restTemplate.execute('myurl/, HttpMethod.GET, _, _) // how can I mock out the expected response here?
0 * _
myFile != null // this fails because myFile is null
After you updated your sample code as I requested, I can see more clearly now. You are suffering from a typical (non-)testability problem: Your method getFile does more than just getting a file. It instantiates two dependencies as local variables, making them unmockable and consequently the whole method mostly untestable.
So you want to refactor for better testability so as to be able to use one testing method I mentioned in my first comment:
If the requestCallback and responseExtractor can be injected via constructor or setter, you can inject mocks.
If they are created by some kind of factory class, you can stub that class.
In case of a factory method inside the class under test itself you can use a spy on the class and stub the factory method.
For a more general discussion of testability and how tests drive application design, see my other answer here, sections "General comments" and "Update".
If any of this is unclear, feel free to ask related(!) follow-up questions.

Cannot get Spring Boot to lazily resolve a multipart file

I have created a Spring Boot 2 demo application with the Spring Initializr and added the controller below:
#Controller
#RequestMapping("/demo")
public class UploadController {
private final static Logger LOG = LoggerFactory.getLogger(UploadController.class);
#PostMapping("/upload")
public ResponseEntity<String> uploadFile(
#RequestParam("metadata") MultipartFile metadata,
#RequestParam("payload") MultipartFile payload) throws IOException {
ObjectMapper mapper = new ObjectMapper();
Map metadataMap = mapper.readValue(metadata.getInputStream(), Map.class);
LOG.info("Received call to upload file {}", metadataMap.get("filename"));
LOG.info("File size: {}", payload.getBytes().length);
LOG.info("File {} successfully uploaded", metadataMap.get("filename"));
return ResponseEntity.ok().build();
}
}
I then added an application.yaml file containing this configuration:
spring:
servlet:
multipart:
max-file-size: 2000000MB
max-request-size: 2000000MB
resolve-lazily: true
My goal is to have the controller parse and log the metadata file before it starts reading the payload file, but the resolve-lazily setting seems to be ignored by Boot: the code inside the controller won't be executed until the whole body is read.
I use the command below to test the controller:
curl -F metadata=#metadata.json -F payload=#payload.bin http://localhost:8080/demo/upload
Is there anything wrong with my code/configuration? Am I getting the meaning of the setting right?
At present, if you want to avoid reading (and buffering) the whole body all at once, I think you will have to provide your own parser, as described in the answers here. What would be really interesting (but generally unnecessary) would be to do so in the form of a new MultipartResolver implementation.
There are two existing implementations documented for interface MultipartResolver, and both supply a function setResolveLazily(boolean) (standard), (commons). I have tried with both, and neither seem to allow for parsing or streaming multipart files or parameters independently.
Default is "false", resolving the multipart elements immediately, throwing corresponding exceptions at the time of the resolveMultipart(javax.servlet.http.HttpServletRequest) call. Switch this to "true" for lazy multipart parsing, throwing parse exceptions once the application attempts to obtain multipart files or parameters.
Despite what it says in the documentation, I have found that once you call resolveMultipart, the entire body is parsed and buffered before the call returns. I know this because I can watch the temp-files being created.
One note about "Is there anything wrong with my code"...
Answer: Yes, because by using #RequestParam you have indirectly asked Spring to resolve your parameters ahead of time, before your controller is ever called. What you should be able to do instead (if the documentation were correct) is request the parameters independently from inside your controller:
Configuration (application.properties):
spring.servlet.multipart.enabled = true
spring.servlet.multipart.resolve-lazily = true
Controller:
#PostMapping(path = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
public ResponseEntity<Void> postUpload(HttpServletRequest rawRequest) {
multipartResolver.setResolveLazily(true); // unclear why this is exists
MultipartHttpServletRequest request = multipartResolver.resolveMultipart(rawRequest);
String p1 = request.getParameter("first-parameter");
String p2 = request.getParameter("second-parameter");
System.out.println("first-parameter="+p1+", second-parameter"+p2);
multipartResolver.cleanupMultipart(request);
return new ResponseEntity<Void>(HttpStatus.ACCEPTED);
}
One useful aspect of resolve-lazily that I have discovered is that it allows you to write your own parser for some rest controllers while using the built-in parser for others (see my answer here). In other words, you don't have to use spring.servlet.multipart.enabled = false to get your parser to work. This is a minor breakthrough relative to other advice that I had seen previously.

How to enable Spring Reactive Web MVC to handle Multipart-file?

I'm trying to use the new reactive web-mvc implementation in a spring boot 2.0 application. I'm trying to define a method which consume multipart file but do not succeed at making it working :( - I always get a 415 error.
On one hand I have a controller containing the following request mapping :
#RequestMapping(method = RequestMethod.POST, path = "/myPath/{param}/{param2}", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
#ResponseBody
public Mono<Void> postFile(
#RequestBody MultipartFile data,
#PathVariable("param") String param,
#PathVariable("param2") String param2,
#RequestHeader(name = HEADER_DATE, required = false) #DateTimeFormat(pattern = DATE_FORMAT) Instant instant
){
return fileService.handleData(Mono.just(data), param, param2, instant);
}
On the other hand I had to add a server on the top of the basic dependencies as it seems netty do not handle multipart files. I so added the spring-boot-starter-tomcatdependency which enabled the MultipartAutoConfiguration to be matched and satisfied on application auto configuration.
When posting something using a curl call :
curl 'Meta-Date: 20170101104532' --form "file=#file.bin" http://localhost:8082/myPath/foo/bar
while debug logs are activated (logging.level.org.springframework.web=DEBUG) I got this exception :
org.springframework.web.server.UnsupportedMediaTypeStatusException: Request failure [status: 415, reason: "Content type 'multipart/form-data;boundary=------------------------58fa43b8f1a26de4' not supported"]
This error is thrown by the RequestBodyArgumentResolver which has the the following supported media types : [*/*, text/xml, application/*+json;charset=UTF-8, application/xml, text/plain;charset=UTF-8, application/x-www-form-urlencoded, application/json;charset=UTF-8] provided by 9 DecoderHttpMessageReader.
Before posting I also took a look at :
Spring MultiPart MediaType Unsupported which seems to not be relevant here as my autoconf report contains the following entry : MultipartAutoConfiguration#multipartResolver matched
set content-type to utf-8 with angularjs $http Adding a header setting Content-Transfer-Encoding: binary didn't changed anything.
My understanding is that Spring web 5.0 uses a new request decoder system as I don't find these classes on a spring 4 spring boot application, and there is not yet any DecoderHttpMessageReader dealing with multipart file
Did I miss something ? Or should I wait one to be implemented ?
Okay, It seems this is just not implemented for now as it currently exists a pull request for this feature : Add reactive multipart request support #1201
Should have check this earlier...
[EDIT] : The issue has been solved and merged into Spring master branch. Should no longer be an issue.
#PutMapping(value="/{..}",consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
public Mono<Void> save(#RequestPart("file") FilePart multipartFormData,#RequestParam("fileName") String fileName,#PathVariable("..") String ..) throws IOException {
List<ByteBuffer> bytesList = new LinkedList<>();
multipartFormData.content().
subscribe(item->bytesList.add(item.asByteBuffer()));
int totalBytes = bytesList.stream().mapToInt(item->item.capacity()).sum();
ByteBuffer buffer = ByteBuffer.allocate(totalBytes);
bytesList.stream().forEach(byteBuff->buffer.put(byteBuff));
baseImageHandler.saveImage(buffer, fileName, baseItemId);
return Mono.empty();
}
Please note that it is a dev verison, but this is how I have managed to do it.

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