I am not an expert in JPA/Hibernate and I really do not know if what I am trying to achieve is not possible or I am doing it wrong and since I expect that is the latter here goes nothing.
I have a Map< Long, Boolean > which I am trying to persist into a table and was following the example described here: Storing a Map<String,String> using JPA
And other examples which basically describe the same practice.
What I was trying to do is:
@Id
private Long id;
@ElementCollection
@CollectionTable(name = "state_map", joinColumns = @JoinColumn(name = "id"))
@MapKeyColumn(name = "name")
@Column(name = "value")
@Type(type = "org.hibernate.type.TrueFalseType")
private Map<Long, Boolean> myBooleanMap;
And my table is defined as:
CREATE TABLE if not exists state_map
(id BIGINT NOT NULL,
name BIGINT NOT NULL,
value CHAR);
But then I get a HibernateException: Wrong column type in STATE_MAP for column value. Found: bigint, expected: char(255)
When I change the bigint to char(255) the entityManager starts but when I am trying to put in the map and persist I am getting a java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Boolean. I suppose that the @Type annotation is applied on the key column instead on the value column.
The only way I managed to make it work is with Map< String, String >. Also I have tried to do everything in the same table which did not work so I have to declare another with just the surrogate id which is mapped to the entity:
CREATE TABLE if not exists state_id
(id serial primary key);
@Entity
@Table(name = "state_id")
public class StateModel {...}
Hope somebody can help, thanks.
UPDATE - SOLUTION
I have solved by introducing an embeddable to wrap the boolean value column:
@Embeddable
class BooleanWrapper{
@Column(name = "value")
@Type(type = "org.hibernate.type.TrueFalseType")
private Boolean myBoolean;}
And my map became:
@ElementCollection
@CollectionTable(name = "state_map", joinColumns = @JoinColumn(name = "id"))
@MapKeyColumn(name = "name")
private Map<Long, BooleanWrapper> myBooleanMap;
