spring boot, jackson and localdate

Question

I use spring boot with mysql

in my application.properties

spring.jpa.generate-ddl=true
spring.jackson.serialization.write-dates-as-timestamps=false

In my build.gradle I have

compile('org.springframework.boot:spring-boot-starter-data-jpa')
compile('org.springframework.boot:spring-boot-starter-data-rest')
compile('org.springframework.boot:spring-boot-starter-web')
compile 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310'

In my java class

import java.time.LocalDate;

@Entity
public class WebSite implements Serializable{

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long webSiteId;

    private LocalDate date;
    ...
}

When this table is created,

date field is created like a TINYBLOB

Why is not a date

Answer 1

This is not an issue with Jackson, but rather that whatever you are using for ORM doesn't know how to convert a Java LocalDate to a MySQL Date.

There are two ways to do this. If you are using Hibernate, you simply include org.hibernate:hibernate-java8 in your dependencies.

Alternatively, if you want just use JPA, you need to create an Attribute Converter. For example:

@Converter(autoApply = true)
public class LocalDateAttributeConverter implements AttributeConverter<LocalDate, Date> {

    @Override
    public Date convertToDatabaseColumn(LocalDate locDate) {
        return (locDate == null ? null : Date.valueOf(locDate));
    }

    @Override
    public LocalDate convertToEntityAttribute(Date sqlDate) {
        return (sqlDate == null ? null : sqlDate.toLocalDate());
    }
}

The Attribute Converter will handle converting between a Java LocalDate and MySQL Date.

See: http://www.thoughts-on-java.org/persist-localdate-localdatetime-jpa/