JsonMapper readValue not mapping byte[] object to POJO class

[marclagula]

Good day!

We are experiencing serialize/deserialize issue during our SpringBoot/Jackson migration of our service. This used to work back in spring-boot 3.5.9/jackson 2, but started becoming an issue when we migrated to spring-boot 4.0.0/jackson 3. For this post, I'll just focus on the deserialize part as solution may also resolve issue encountered with serializing (mapper.writeValueAsBytes(..)) into Java POJO (also returns null).

This is the IndividualDetails and IndividualName openapi generated POJO classes:

IndividualDetails.class

@JsonPropertyOrder({
  IndividualResponse.JSON_PROPERTY_INDIVIDUAL_NAME,
  IndividualResponse.JSON_PROPERTY_CUSTOMER_ID
})
@com.fasterxml.jackson.annotation.JsonInclude(com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL)
@com.fasterxml.jackson.annotation.JsonIgnoreProperties(ignoreUnknown=true)
@lombok.Data
@lombok.Builder
@lombok.AllArgsConstructor
@jakarta.annotation.Generated(value = "...", comments = "Generator version: 7.19.0")
public class IndividualResponse implements Serializable {
  private static final long serialVersionUID = 1L;

  public static final String JSON_PROPERTY_INDIVIDUAL_NAME = "individualName";
  @jakarta.annotation.Nullable
  private IndividualName individualName;
   /**
   * Get individualName
   * @return individualName
   */
  @jakarta.annotation.Nullable
  @JsonProperty(value = JSON_PROPERTY_INDIVIDUAL_NAME, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public IndividualName getIndividualName() {
    return individualName;
  }

  @JsonProperty(value = JSON_PROPERTY_INDIVIDUAL_NAME, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setIndividualName(@jakarta.annotation.Nullable IndividualName individualName) {
    this.individualName = individualName;
  }
...
...

IndividualName.class

/**
 * IndividualName
 */
@JsonPropertyOrder({
  IndividualName.JSON_PROPERTY_LAST_NAME,
  IndividualName.JSON_PROPERTY_FIRST_NAME1,
  IndividualName.JSON_PROPERTY_FIRST_NAME2
})
@com.fasterxml.jackson.annotation.JsonInclude(com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL)
@com.fasterxml.jackson.annotation.JsonIgnoreProperties(ignoreUnknown=true)
@lombok.Data
@lombok.Builder
@lombok.AllArgsConstructor
@jakarta.annotation.Generated(value = "...", comments = "Generator version: 7.19.0")
public class IndividualName implements Serializable {
  private static final long serialVersionUID = 1L;

  public static final String JSON_PROPERTY_LAST_NAME = "lastName";
  @jakarta.annotation.Nullable
  private String lastName;

  public static final String JSON_PROPERTY_FIRST_NAME1 = "firstName1";
  @jakarta.annotation.Nullable
  private String firstName1;

  public static final String JSON_PROPERTY_FIRST_NAME2 = "firstName2";
  @jakarta.annotation.Nullable
  private String firstName2;

  public IndividualName() { 
  }

  public IndividualName lastName(@jakarta.annotation.Nullable String lastName) {
    this.lastName = lastName;
    return this;
  }

  /**
   * Get lastName
   * @return lastName
   */
  @jakarta.annotation.Nullable
  @JsonProperty(value = JSON_PROPERTY_LAST_NAME, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public String getLastName() {
    return lastName;
  }


  @JsonProperty(value = JSON_PROPERTY_LAST_NAME, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setLastName(@jakarta.annotation.Nullable String lastName) {
    this.lastName = lastName;
  }

  public IndividualName firstName1(@jakarta.annotation.Nullable String firstName1) {
    this.firstName1 = firstName1;
    return this;
  }

  /**
   * Get firstName1
   * @return firstName1
   */
  @jakarta.annotation.Nullable
  @JsonProperty(value = JSON_PROPERTY_FIRST_NAME1, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public String getFirstName1() {
    return firstName1;
  }

  @JsonProperty(value = JSON_PROPERTY_FIRST_NAME1, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setFirstName1(@jakarta.annotation.Nullable String firstName1) {
    this.firstName1 = firstName1;
  }

  public IndividualName firstName2(@jakarta.annotation.Nullable String firstName2) {
    this.firstName2 = firstName2;
    return this;
  }

  /**
   * Get firstName2
   * @return firstName2
   */
  @jakarta.annotation.Nullable
  @JsonProperty(value = JSON_PROPERTY_FIRST_NAME2, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public String getFirstName2() {
    return firstName2;
  }


  @JsonProperty(value = JSON_PROPERTY_FIRST_NAME2, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setFirstName2(@jakarta.annotation.Nullable String firstName2) {
    this.firstName2 = firstName2;
  }
...
...

This is our JsonMapper configuration:

JsonMapper objectMapper = JsonMapper.builder()
.changeDefaultPropertyInclusion(incl ->
   incl.withValueInclusion(JsonInclude.Include.NON_NULL)
)
.disable(DateTimeFeature.WRITE_DATES_AS_TIMESTAMPS)
.disable(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)
.build();

When we try to log the byte[] content (converted to string), we get the correct value:

byte[] idvState = idvCase.getIndividualDetails(); // individualDetails is a BLOB byte[] field
log.info("ID&V Case: [{}] - [{}] - [{}]", 
idvCase.getCaseId(), idvCase.getCaseStatus(), new String(idvState, StandardCharsets.UTF_8));


DISPLAYS:


ID&V Case: [CASE-484] - [CLOSED_SUCCESS] - [{"individualName":{"lastName":"Doe","firstName1":"John","firstName2":"Mayer"},...,"customerId":12345678}]

But when we log the mapper deserialized one:

log.info("Converted by mapper: {}", objectMapper.readValue(idvState, IndividualResponse.class));


DISPLAYS:


Converted by mapper: null

This is our jackson libs in pom (maintained by jackson-bom v3.0.4):

<dependency>
   <groupId>tools.jackson.core</groupId>
   <artifactId>jackson-databind</artifactId>
</dependency>
<dependency>
   <groupId>tools.jackson.core</groupId>
   <artifactId>jackson-core</artifactId>
</dependency>
<dependency>
   <groupId>com.fasterxml.jackson.core</groupId>
   <artifactId>jackson-annotations</artifactId>
</dependency>

We already tried to add .enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES) on our mapper configuration, but it doesn't fail on deserializing the byte[], just returns null.

Any leads or advise on this finding is appreciated!

[cowtowncoder]

First thing is that Lombok annotations need to be removed -- that is, we'd need de-lombokified version.

Second would be to enable DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES which may show actual problems (default was changed to disabled in 3.0) but sounds like you already tries that.

[marclagula]

I’ll try that and let you know.

But just out of curiosity: why is lombok suddenly unsupported for Jackson3 when it worked back in Jackson2?

[marclagula]

I have de-lombokified all of the openapi-generated classes but mapper.readValue still returns null

LOG STRING-CONVERTED BYTE[ ]:

log.info("ID&V Case: [{}] - [{}] - [{}]", 

DISPLAYS:

idvCase.getCaseId(), idvCase.getCaseStatus(), new String(idvState, StandardCharsets.UTF_8));
ID&V Case: [CASE-477] - [CLOSED_SUCCESS] - [{"individualName":{"lastName":"Gerbennowdcfqs","firstName1":"Martenoydhg","firstName2":"Tarikdstti",..."customerId":12345678}]

LOG MAPPER CONVERTED BYTE[ ]:

log.info("Converted by mapper: {}", kycObjectMapper.readValue(idvState, IndividualResponse.class));

DISPLAYS:

Converted by mapper: null

The de-lombokified POJO class:

IndividualResponse

/**
 * IndividualResponse
 */
@JsonPropertyOrder({
  IndividualResponse.JSON_PROPERTY_INDIVIDUAL_NAME,
  IndividualResponse.JSON_PROPERTY_CUSTOMER_ID
})
@com.fasterxml.jackson.annotation.JsonInclude(com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL)
@com.fasterxml.jackson.annotation.JsonIgnoreProperties(ignoreUnknown=true)
@jakarta.annotation.Generated(value = "...", comments = "Generator version: 7.19.0")
public class IndividualResponse implements Serializable {
  private static final long serialVersionUID = 1L;

  public static final String JSON_PROPERTY_INDIVIDUAL_NAME = "individualName";
  @jakarta.annotation.Nullable
  private IndividualName individualName;
  /**
   * Get individualName
   * @return individualName
   */
  @jakarta.annotation.Nullable
  @JsonProperty(value = JSON_PROPERTY_INDIVIDUAL_NAME, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public IndividualName getIndividualName() {
    return individualName;
  }

  @JsonProperty(value = JSON_PROPERTY_INDIVIDUAL_NAME, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setIndividualName(@jakarta.annotation.Nullable IndividualName individualName) {
    this.individualName = individualName;
  }

  public IndividualResponse individualName(@jakarta.annotation.Nullable IndividualName individualName) {
    this.individualName = individualName;
    return this;
  }

IndividualName:

/**
 * IndividualName
 */
@JsonPropertyOrder({
  IndividualName.JSON_PROPERTY_LAST_NAME,
  IndividualName.JSON_PROPERTY_FIRST_NAME1,
  IndividualName.JSON_PROPERTY_FIRST_NAME2
})
@com.fasterxml.jackson.annotation.JsonInclude(com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL)
@com.fasterxml.jackson.annotation.JsonIgnoreProperties(ignoreUnknown=true)
@jakarta.annotation.Generated(value = "...", comments = "Generator version: 7.19.0")
public class IndividualName implements Serializable {
  private static final long serialVersionUID = 1L;

  public static final String JSON_PROPERTY_LAST_NAME = "lastName";
  @jakarta.annotation.Nullable
  private String lastName;

  public static final String JSON_PROPERTY_FIRST_NAME1 = "firstName1";
  @jakarta.annotation.Nullable
  private String firstName1;

  public static final String JSON_PROPERTY_FIRST_NAME2 = "firstName2";
  @jakarta.annotation.Nullable
  private String firstName2;

  public IndividualName lastName(@jakarta.annotation.Nullable String lastName) {
    this.lastName = lastName;
    return this;
  }

  /**
   * Get lastName
   * @return lastName
   */
  @jakarta.annotation.Nullable
  @JsonProperty(value = JSON_PROPERTY_LAST_NAME, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public String getLastName() {
    return lastName;
  }


  @JsonProperty(value = JSON_PROPERTY_LAST_NAME, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setLastName(@jakarta.annotation.Nullable String lastName) {
    this.lastName = lastName;
  }


  public IndividualName firstName1(@jakarta.annotation.Nullable String firstName1) {
    this.firstName1 = firstName1;
    return this;
  }

  /**
   * Get firstName1
   * @return firstName1
   */
  @jakarta.annotation.Nullable
  @JsonProperty(value = JSON_PROPERTY_FIRST_NAME1, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public String getFirstName1() {
    return firstName1;
  }


  @JsonProperty(value = JSON_PROPERTY_FIRST_NAME1, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setFirstName1(@jakarta.annotation.Nullable String firstName1) {
    this.firstName1 = firstName1;
  }


  public IndividualName firstName2(@jakarta.annotation.Nullable String firstName2) {
    this.firstName2 = firstName2;
    return this;
  }

  /**
   * Get firstName2
   * @return firstName2
   */
  @jakarta.annotation.Nullable
  @JsonProperty(value = JSON_PROPERTY_FIRST_NAME2, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public String getFirstName2() {
    return firstName2;
  }


  @JsonProperty(value = JSON_PROPERTY_FIRST_NAME2, required = false)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setFirstName2(@jakarta.annotation.Nullable String firstName2) {
    this.firstName2 = firstName2;
  }

Again, have tried enabling and disabling FAIL_ON_UNKNOWN_PROPERTIES but to no avail. Any leads?

[marclagula]

Nevermind, it was a case of misconfiguration of the JsonMapper in my unit test class. It has nothing to do with the Lombok annotation as it still worked when I reverted back the Lombok annotations in the openapi-generated POJO classes.

Thanks alot for the lead!

[JooHyukKim]

Thank you for the update @marclagula !