Styjun

I'm making a POST route using akka, where I'm deserializing my Json data into Video object, but the following curl request:

curl -H "Content-Type: application/json" -X POST -d '"title": "Video Title","videoDate":"10-2-2018","videoTime":"12:10:11"' http://localhost:9090/updatedData

gives an error: Cannot unmarshal JSON as Video

The request works fine when I remove videoDate and videoTime fields from json.

Jackson.unmarshaller(VideoInfo.class)

//Video.class
public class Video 
 private String title;
 private LocalDate videoDate;
 private LocalTime videoTime;

The maven dependency used is

<dependency>
 <groupId>com.fasterxml.jackson.core</groupId>
 <artifactId>jackson-annotations</artifactId>
 <version>2.9.8</version>
</dependency>

Here's my route /updatedData

post(() ->
 path("updatedData", () -> 
 LOGGER.info("calling POST /updatedData");
 return entity(Jackson.unmarshaller(Video.class), videoInfo -> 
 LOGGER.debug("Payload received : " + videoInfo.toString());
 ArrayList<HttpHeader> headers = getCORSHeaders();
 return respondWithHeaders(headers, () ->
 onSuccess(videoFrameProcessing.updateVideoInfo(videoInfo), this::complete));
 );
 )),

Jackson requires an additional module for the Java 8 Time API.

The module

jackson-datatype-jsr310

has been deprecated and is now part of

jackson-modules-java8

<dependency>
 <groupId>com.fasterxml.jackson.datatype</groupId>
 <artifactId>jackson-datatype-jsr310</artifactId>
 <version>2.9.8</version>
</dependency>

Which means you need to register that module manually

final ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new JavaTimeModule());

The Akka Jackson class offers an overloaded version of unmarshaller, which you can use to pass a customized version of ObjectMapper

public static <T> Unmarshaller<HttpEntity, T> unmarshaller(ObjectMapper mapper, Class<T> expectedType) 
 return Unmarshaller.forMediaType(MediaTypes.APPLICATION_JSON, Unmarshaller.entityToString())
 .thenApply(s -> fromJSON(mapper, s, expectedType));

So, instead of

Jackson.unmarshaller(Video.class)

use

Jackson.unmarshaller(objectMapper, Video.class);

The objectMapper parameter is the custom ObjectMapper

final ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new JavaTimeModule());

The complete snippet would be

post(() ->
 path("updatedData", () -> 
 LOGGER.info("calling POST /updatedData");

 final ObjectMapper objectMapper = new ObjectMapper();
 objectMapper.registerModule(new JavaTimeModule());

 return entity(Jackson.unmarshaller(objectMapper, Video.class), videoInfo -> 
 LOGGER.debug("Payload received : " + videoInfo.toString());
 ArrayList<HttpHeader> headers = getCORSHeaders();
 return respondWithHeaders(headers, () ->
 onSuccess(videoFrameProcessing.updateVideoInfo(videoInfo), this::complete));
 );
 )),

Obviously, extract the ObjectMapper as a "global" variable.