A custom UserType that enables Hibernate to map a Java integer array to a PostgreSQL integer array.

IntegerArrayType.java

public class IntegerArrayType implements UserType {
    protected static final int  SQLTYPE = java.sql.Types.ARRAY;

    @Override
    public Object nullSafeGet(final ResultSet rs, final String[] names, final SessionImplementor sessionImplementor, final Object owner) throws HibernateException, SQLException {
        Array array = rs.getArray(names[0]);
        Integer[] javaArray = (Integer[]) array.getArray();
        return ArrayUtils.toPrimitive(javaArray);
    }

    @Override
    public void nullSafeSet(final PreparedStatement statement, final Object object, final int i, final SessionImplementor sessionImplementor) throws HibernateException, SQLException {
        Connection connection = statement.getConnection();

        int[] castObject = (int[]) object;
        Integer[] integers = ArrayUtils.toObject(castObject);
        Array array = connection.createArrayOf("integer", integers);

        statement.setArray(i, array);
    }

    @Override
    public Object assemble(final Serializable cached, final Object owner) throws HibernateException {
        return cached;
    }

    @Override
    public Object deepCopy(final Object o) throws HibernateException {
        return o == null ? null : ((int[]) o).clone();
    }

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

    @Override
    public boolean equals(final Object x, final Object y) throws HibernateException {
        return x == null ? y == null : x.equals(y);
    }

    @Override
    public int hashCode(final Object o) throws HibernateException {
        return o == null ? 0 : o.hashCode();
    }

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

    @Override
    public Object replace(final Object original, final Object target, final Object owner) throws HibernateException {
        return original;
    }

    @Override
    public Class<int[]> returnedClass() {
        return int[].class;
    }

    @Override
    public int[] sqlTypes() {
        return new int[] { SQLTYPE };
    }
}

Hi! Thanks for posting this class. The column with the integer array had some null values in my case; I needed to change the 'nullsafeGet' to

  Array array = rs.getArray(names[0]);
        if(array!=null) {

            Integer[] javaArray = (Integer[]) array.getArray();
            return ArrayUtils.toPrimitive(javaArray);

        }
        return ArrayUtils.toPrimitive(new Integer[0]);