I have a json as a string:

{
    "passnummer": "passnummer",
    "nummerDesAufenthaltstitels": "nummerDesAufenthaltstitels",
    "ppkNummer": "ppkNummer",
    "fingerabdruckreferenznummer": "fingerabdruckreferenznummer"
}

there is no consistency for the seperation of the words meaning that some keys are camel case and some are not. I have no influence on that. And I cannot change the model.

I have to read this string into a Java Object. I also have no influennce on the Java Model so I cannot add @JsonProperty or @JsonAlias annotations or anything else to the fields of the model.

So the java model looks like this:

  public static class Request {
    protected String passnummer;
    protected String nummerDesAufenthaltstitels;
    protected String ppkNummer;
    protected String fingerabdruckreferenznummer;

    public String getPassnummer() {
      return this.passnummer;
    }

    public void setPassnummer(String value) {
      this.passnummer = value;
    }

    public String getNummerDesAufenthaltstitels() {
      return this.nummerDesAufenthaltstitels;
    }

    public void setNummerDesAufenthaltstitels(String value) {
      this.nummerDesAufenthaltstitels = value;
    }

    public String getPpkNummer() {
      return this.ppkNummer;
    }

    public void setPpkNummer(String value) {
      this.ppkNummer = value;
    }

    public String getFingerabdruckreferenznummer() {
      return this.fingerabdruckreferenznummer;
    }

    public void setFingerabdruckreferenznummer(String value) {
      this.fingerabdruckreferenznummer = value;
    }
}

When I deserialize the json into the java object and print the values:

Request request = objectmapper.readValue(jsonPayload, Request.class);

System.out.println("passnummer: "   request.getPassnummer());
System.out.println("nummerDesAufenthaltstitels: "   request.getNummerDesAufenthaltstitels());
System.out.println("ppkNummer: "   request.getPpkNummer());
System.out.println("fingerabdruckreferenznummer: "   request.getFingerabdruckreferenznummer());

I get the following result:

passnummer: passnummer
nummerDesAufenthaltstitels: nummerDesAufenthaltstitels
ppkNummer: ppkNummer
fingerabdruckreferenznummer: null

So my question is: Why cant objectMapper desieralize fingerabdruckreferenznummer?

EDIT

ObjectMapper config:

  public ObjectMapper objectMapper() {
    final ObjectMapper objectMapper = new ObjectMapper();
    final SimpleModule module = new SimpleModule();

    module.addSerializer(TeilbekanntesDatumMitUnbekannt.class, new DateSerializer());

    objectMapper.registerModule(module);
    objectMapper.registerModule(new JavaTimeModule());
    objectMapper.registerModule(new JaxbAnnotationModule());
    objectMapper.configure(WRITE_DATES_AS_TIMESTAMPS, false);

    objectMapper.configure(FAIL_ON_UNKNOWN_PROPERTIES, false);
    objectMapper.setVisibility(objectMapper.getSerializationConfig().getDefaultVisibilityChecker()
        .withFieldVisibility(JsonAutoDetect.Visibility.ANY)
        .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
        .withSetterVisibility(JsonAutoDetect.Visibility.NONE)
        .withCreatorVisibility(JsonAutoDetect.Visibility.NONE));

    return objectMapper;
  }

EDIT 2

If I use a play new ObjectMapper() instead I get:

com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "fingerabdruckreferenznummer"

CodePudding user response：

Using your ObjectMapper (except the parts that you didn't post) and this code, the result is as expected:

Code

    final ObjectMapper objectMapper = new ObjectMapper();
    final SimpleModule module = new SimpleModule();
    //        module.addSerializer(TeilbekanntesDatumMitUnbekannt.class, new DateSerializer());
    //            objectMapper.registerModule(new JaxbAnnotationModule());

    objectMapper.registerModule(module);
    objectMapper.registerModule(new JavaTimeModule());
    objectMapper.configure(WRITE_DATES_AS_TIMESTAMPS, false);

    objectMapper.configure(FAIL_ON_UNKNOWN_PROPERTIES, false);
    objectMapper.setVisibility(objectMapper.getSerializationConfig().getDefaultVisibilityChecker()
            .withFieldVisibility(JsonAutoDetect.Visibility.ANY)
            .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
            .withSetterVisibility(JsonAutoDetect.Visibility.NONE)
            .withCreatorVisibility(JsonAutoDetect.Visibility.NONE));


    final String jsonPayload = """
             {
                 "passnummer": "1passnummer",
                 "nummerDesAufenthaltstitels": "2nummerDesAufenthaltstitels",
                 "ppkNummer": "3ppkNummer",
                 "fingerabdruckreferenznummer": "4fingerabdruckreferenznummer"
             }               
            """;
    final Request request = objectMapper.readValue(jsonPayload, Request.class);

    System.out.println("passnummer: "   request.getPassnummer());
    System.out.println("nummerDesAufenthaltstitels: "   request.getNummerDesAufenthaltstitels());
    System.out.println("ppkNummer: "   request.getPpkNummer());
    System.out.println("fingerabdruckreferenznummer: "   request.getFingerabdruckreferenznummer());

Result

passnummer: 1passnummer
nummerDesAufenthaltstitels: 2nummerDesAufenthaltstitels
ppkNummer: 3ppkNummer
fingerabdruckreferenznummer: 4fingerabdruckreferenznummer

So either your json-payload is different, or your objectmapper has some additional config.

CodePudding user response：

The ObjectMapper could be configured to filter out certain fields. Create you own ObjectMapper or make sure you know what is configured. This could be done with a Mixin.

this.objectMapper = objectMapper.addMixIn(Request.class, MyMixin.class);

@JsonIgnoreProperties({"fingerabdruckreferenznummer", "field2"})
private interface MyMixin {}