Jackson unable to consider @XmlElement while serializing to JSON

Question

I have a contract class that contains elements with @XmlElement tags. For ex

 @XmlElement(name = "balancemoney")
 protected Amount balanceMoney;

Using the JAXBContext I am able to generate the xml with proper tags.

However, when I use the jackson provided library, the JSON tag still comes in as 'balanceMoney' instead of 'balancemoney'

How do I tell Jackson to consider the @XmlElement tag.

Below is the code which does this.

    //Function to display request object.
public void displayXML(Object reqResp){
    try{
        JAXBContext jaxbContext = JAXBContext.newInstance(reqResp.getClass());
        Marshaller jaxbMarshaller = jaxbContext.createMarshaller();

        // output pretty printed
        jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

        ByteArrayOutputStream bStream=new ByteArrayOutputStream();

        //jaxbMarshaller.marshal(reqResp, System.out);
        jaxbMarshaller.marshal(reqResp,bStream );

        logger.info(bStream.toString());    

        }catch(JAXBException e){
            logger.info(e.getMessage());
        }
        logger.info("*** Payload is: " + reqResp.toString());
}

//Function to display as JSON
public void displayJSON(Object reqResp) throws JsonGenerationException, JsonMappingException, IOException{
    ObjectMapper mapper = new ObjectMapper();
    logger.info(mapper.defaultPrettyPrintingWriter().writeValueAsString(reqResp));

}

Answer 1

• Maven dependency - pom.xml:

  <dependency>
      <groupId>com.fasterxml.jackson.module</groupId>
      <artifactId>jackson-module-jaxb-annotations</artifactId>
      <version>2.6.1</version>
  </dependency>
  

• Custom ObjectMapper configuration (uncomment all annotations to register this mapper as default in Spring):

  //@Configuration
  public class JacksonConfig {
  
      //@Primary
      //@Bean
      public static ObjectMapper createCustomObjectMapper() {
          ObjectMapper mapper = new ObjectMapper();
          AnnotationIntrospector aiJaxb = new JaxbAnnotationIntrospector(TypeFactory.defaultInstance());
          AnnotationIntrospector aiJackson = new JacksonAnnotationIntrospector();
          // first Jaxb, second Jackson annotations
          mapper.setAnnotationIntrospector(AnnotationIntrospector.pair(aiJaxb, aiJackson));
          return mapper;
      }
  }
  

• Code to display as JSON:

  public void displayJSON(Object reqResp) throws JsonProcessingException{
      ObjectMapper mapper = JacksonConfig.createCustomObjectMapper();
      LOG.info(mapper.writeValueAsString(reqResp));
  }
  

Answer 2

According to Using JAXB annotations with Jackson: Enabling JAXB annotation support, you need to set mapper.getDeserializationConfig().setAnnotationIntrospector(new JaxbAnnotationIntrospector()); to enable Jackson to use JAXB annotation.