Persisting UUID in PostgreSQL using JPA

Question

I\'m trying to persist an entity in PostgreSQL that uses UUID as primary key. I\'ve tried persisting it as a plain UUID:

@Id
@Column(name = \"customer_id\")
         


        

Answer 1

I am sure, that once you generated UUID for a record, it will be static. Thus there is no point in mapping UUID as an object to database and then converting it back to String on retrieval.

Use UUID as a String:

@Id
@Column(name = "customer_id")
private String id;

//getter and setter

public void setId(UUID id) {
    this.id = id.toString();
}

Also there are some things to consider:

1. Whether to use ID, UUID or both. There is quick discussion over this.
2. Using 'uuid' for names rather than 'id', it is misleading.
3. Removing '-' signs from UUID, save 4 bytes.
4. Generating UUID in @PrePersist section if you use Spring.

Answer 2

To have it working with Hibernate 5.1.x, you can follow Steve Ebersole comment here

@Id
@GeneratedValue
@Column( columnDefinition = "uuid", updatable = false )
public UUID getId() {
    return id;
}

Answer 3

JPA 2.1 provides a very easy way to use the PostgreSQL uuid column type and java.util.UUID as the type of the corresponding entity field:

@javax.persistence.Converter(autoApply = true)
public class PostgresUuidConverter implements AttributeConverter<UUID, UUID> {

    @Override
    public UUID convertToDatabaseColumn(UUID attribute) {
        return attribute;
    }

    @Override
    public UUID convertToEntityAttribute(UUID dbData) {
        return dbData;
    }

}

Just add this class to your persistence configuration and annotate UUID fields with @Column(columnDefinition="uuid").

Answer 4

Newer version >= 8.4-701 of Postgresql JDBC driver correctly handle java.util.UUID mapping. And so do Hibernate >= 4.3.x.

See details on https://stackoverflow.com/a/780922/173149:

Map the database uuid type to java.util.UUID.
This only works for relatively new server (8.3) and JDK (1.5) versions.

Answer 5

The PostgreSQL JDBC driver has chosen an unfortunately way to represent non-JDBC-standard type codes. They simply map all of them to Types.OTHER. Long story short, you need to enable a special Hibernate type mapping for handling UUID mappings (to columns of the postgres-specific uuid datatype):

@Id
@Column(name = "customer_id")
@org.hibernate.annotations.Type(type="org.hibernate.type.PostgresUUIDType")
private UUID id;

or more succinctly:

@Id
@Column(name = "customer_id")
@org.hibernate.annotations.Type(type="pg-uuid")
private UUID id;

Another (better) option is to register org.hibernate.type.PostgresUUIDType as the default Hibernate type mapping for all attributes exposed as java.util.UUID. That is covered in the documentation @ http://docs.jboss.org/hibernate/orm/4.1/manual/en-US/html/ch06.html#types-registry

Answer 6

The solution suggested by Oleg did not work perfectly for me (it failed if you tried to persist a null value). Here is a tweaked solution that also works for null values.

In my case i am using EclipseLink though so if you are using Hibernate you might not need this.

public class UuidConverter implements AttributeConverter<UUID, Object> {
    @Override
    public Object convertToDatabaseColumn(UUID uuid) {
        PGobject object = new PGobject();
        object.setType("uuid");
        try {
            if (uuid == null) {
                object.setValue(null);
            } else {
                object.setValue(uuid.toString());
            }
        } catch (SQLException e) {
            throw new IllegalArgumentException("Error when creating Postgres uuid", e);
        }
        return object;
    }

    @Override
    public UUID convertToEntityAttribute(Object dbData) {
        return (UUID) dbData;
    }
}