Field is updated to null while updating table

I am updating a table using JPA. Postgres is the DB. There is a field which is of type String[] . While updating through API , other fields are getting updated. but this String[] field is updating to null . I have implemented by taking reference of https://www.baeldung.com/java-hibernate-map-postgresql-array . Any help is appreciated

CustomMapper.java

public class CustomStringArrayType implements UserType {

        @Override
        public int[] sqlTypes() {
            return new int[]{Types.ARRAY};
        }

        @Override
        public Class returnedClass() {
            return Integer[].class;
        }

    @Override
    public boolean equals(Object o, Object o1) throws HibernateException {
        return false;
    }

    @Override
    public int hashCode(Object o) throws HibernateException {
        return 0;
    }

    @Override
        public Object nullSafeGet(ResultSet rs, String[] names, SharedSessionContractImplementor session, Object owner)
                throws HibernateException, SQLException {
            Array array = rs.getArray(names[0]);
            return array != null ? array.getArray() : null;
        }

        @Override
        public void nullSafeSet(PreparedStatement st, Object value, int index, SharedSessionContractImplementor session)
                throws HibernateException, SQLException {
            if (value != null && st != null) {
                Array array = session.connection().createArrayOf("int", (Integer[])value);
                st.setArray(index, array);
            } else {
                st.setNull(index, sqlTypes()[0]);
            }
        }

    @Override
    public Object deepCopy(Object o) throws HibernateException {
        return null;
    }

    @Override
    public boolean isMutable() {
        return false;
    }

    @Override
    public Serializable disassemble(Object o) throws HibernateException {
        return null;
    }

    @Override
    public Object assemble(Serializable serializable, Object o) throws HibernateException {
        return null;
    }

    @Override
    public Object replace(Object o, Object o1, Object o2) throws HibernateException {
        return null;
    }

Update Part:

@Override
  public CompletableFuture<Void> updateContactGroup_1_0(
      ContactGroupDTO contactGroupDTO, String groupId, String fleetId) {
    var contactGroupEntity =
        contactGroupRepository.findContactGroupByGroupAndFleetId(Long.parseLong(groupId), fleetId);
    if (contactGroupEntity == null) {
      throw new BadRequestException("Group doesn't exist !!");
    } else {
      return CompletableFuture.supplyAsync(
          () -> {
            contactGroupRepository.save(
                ContactGroupMapper.updateInDB(
                    contactGroupDTO, groupId, fleetId, contactGroupEntity.getCreatedTime()));
            return null;
          },
          RepositoryUtil.executor());
    }
  }

Answer

You want to map String[] but your CustomStringArrayType maps Integer[]. Look at your code:

@Override
public Class returnedClass() {
    return Integer[].class;
}

and:

Array array = session.connection().createArrayOf("int", (Integer[])value);

this should be changed to:

@Override
public Class returnedClass() {
    return String[].class;
}

and:

Array array = session.connection().createArrayOf("text", (String[])value);