SpringBoot: Persist nested JSON [using spring-boot-starter-data-rest + sql]

fseb :

I have the following POST request:

{
    "name": "Peter",
    "lastName": "Smith", 
    "contact": {
        "phone":"12345679",
        "email": "[email protected]"
    }
}

And I would like to store that in a SQL DB as follow:

I'm using spring-boot-starter-data-rest so I only have the UserRepository and User Entity, which has an Embedded property contact

User.java

@Entity
@Table(name="user")
public class User {

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

    @Column(name = "name")
    private String title;

    @Column(name = "lastName")
    private String lastName;

    @Embedded
    @Column(name = "contact")
    private Contact contact;


 }

Contact.java

@Embeddable
public class Contact {
   private String phone;
   private String email;
}

UserRepository.java

public interface UserRepository extends JpaRepository<User, Integer> {
    //     
}

If I make a POST request I get an error, because (guess) I'm not converting Contact to JSON.

I've already tried adding a @Convert(converter = HashMapConverter.class) but I get an error.

HashMapConverter

public class HashMapConverter implements AttributeConverter<Object, String> {

    private static final ObjectMapper om = new ObjectMapper();

    @Override
    public String convertToDatabaseColumn(Object attribute) {
        try {
            return om.writeValueAsString(attribute);
        } catch (JsonProcessingException ex) {
            //log.error("Error while transforming Object to a text datatable column as json string", ex);
            return null;
        }
    }

    @Override
    public Object convertToEntityAttribute(String dbData) {
        try {
            return om.readValue(dbData, Object.class);
        } catch (IOException ex) {
            //log.error("IO exception while transforming json text column in Object property", ex);
            return null;
        }
    }

}

zpavel :

i've got the same case for storing json field which is working perfectly. Please try :

Add dependency to pom.xml :

<dependency>
    <groupId>com.vladmihalcea</groupId>
    <artifactId>hibernate-types-52</artifactId>
    <version>2.9.7</version>
</dependency>

Edit User class within :

@Entity
@TypeDef(name = "json", typeClass = JsonStringType.class)
public class User {
    // other field here
    @Type(type = "json")
    @Column(columnDefinition = "json")
    private Contact contact;
    // getters, setters
}

Of course your database should support json type. For MariaDB for example you can refer to https://mariadb.com/kb/en/json-data-type/