Spring Boot LocalDate field serialization and deserialization

Question

In Spring Boot 1.2.3.RELEASE with fasterxml what is the correct way of serializing and de-serializing a LocalDate field to ISO date formatted string?

I've tried:

• spring.jackson.serialization.write-dates-as-timestamps:false in application.properties file,

• including jackson-datatype-jsr310 in project and then using

  • @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd") annotation

  • and @DateTimeFormat(iso=ISO.DATE) annotation,

• adding Jsr310DateTimeFormatAnnotationFormatterFactory as formatter with:

  @Override
  public void addFormatters(FormatterRegistry registry) {
      registry.addFormatterForFieldAnnotation(new Jsr310DateTimeFormatAnnotationFormatterFactory());
  }
  

None of the above helped.

Answer 1

In my Spring Boot 2 applications

• @JsonFormat annotation is used in REST controllers when (de)serializing JSON data.
• @DateTimeFormat annotation is used in other controllers ModelAttributes when (de)serializing String data.

You can specify both on the same field (useful if you share DTO between JSON and Thymeleaf templates):

@JsonFormat(pattern = "dd/MM/yyyy") 
@DateTimeFormat(pattern = "dd/MM/yyyy")
private LocalDate birthdate;

Gradle dependency:

implementation group: 'org.springframework.boot', name: 'spring-boot-starter-json'

I hope this is all configuration you need for custom Date/Time formatting in Spring Boot 2.x apps.

---

For Spring Boot 1.x apps, specify additional annotations and dependency:

@JsonFormat(pattern = "dd/MM/yyyy")
@DateTimeFormat(pattern = "dd/MM/yyyy")
@JsonDeserialize(using = LocalDateDeserializer.class)
@JsonSerialize(using = LocalDateSerializer.class)
private LocalDate birthDate;

// or
@JsonFormat(pattern = "dd/MM/yyyy HH:mm")
@DateTimeFormat(pattern = "dd/MM/yyyy HH:mm")
@JsonDeserialize(using = LocalDateTimeDeserializer.class)
@JsonSerialize(using = LocalDateTimeSerializer.class)
private LocalDateTime birthDateTime;

implementation group: 'com.fasterxml.jackson.datatype', name: 'jackson-datatype-jsr310', version: '2.9.8'

---

Be aware that your API will throw "JSON parse error" if somebody sends a date in a wrong format. Mapping example:

@JsonFormat(pattern = "yyyy-MM-dd")
private LocalDate releaseDate;

Exception example:

HttpMessageNotReadableException: JSON parse error: Cannot deserialize value of type java.time.LocalDate from String "2002": Failed to deserialize java.time.LocalDate: (java.time.format.DateTimeParseException) Text '2002' could not be parsed at index 4; nested exception is com.fasterxml.jackson.databind.exc.InvalidFormatException: Cannot deserialize value of type java.time.LocalDate from String "2002": Failed to deserialize java.time.LocalDate: (java.time.format.DateTimeParseException) Text '2002' could not be parsed at index 4