Float array jpa Mapping

Question

I have an array of floats as one of the columns in my table. I'm having trouble mapping it with JPA. Can someone help?

I am moving my service from ruby on rails to spring boot. For Example. It looks like this in the rails console.

 billing_ids : [
    [0] 27295
    [1] 21323
]

Answer 1

You need to add the below maven dependency

        <dependency>
            <groupId>com.vladmihalcea</groupId>
            <artifactId>hibernate-types-52</artifactId>
            <version>2.2.0</version>
        </dependency>

Map the Integer array column as below

    @Type(type = "test.GenericArrayUserType")
    private Integer[] billing_ids;

define the GenericArrayUserType class as below

public class GenericArrayUserType<T extends Serializable> implements UserType {

    protected static final int[] SQL_TYPES = { Types.ARRAY };
    private  Class<T> typeParameterClass;

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

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

    @SuppressWarnings("unchecked")
    @Override
    public Serializable disassemble(Object value) throws HibernateException {
        return (T) this.deepCopy(value);
    }

    @Override
    public boolean equals(Object x, Object y) throws HibernateException {

        if (x == null) {
            return y == null;
        }
        return x.equals(y);
    }

    @Override
    public int hashCode(Object x) throws HibernateException {
        return x.hashCode();
    }

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

    @Override
    public Object nullSafeGet(ResultSet resultSet, String[] names, SessionImplementor session, Object owner)
            throws HibernateException, SQLException {

        if (resultSet.getArray(names[0]) == null) {
            return new Integer[0];
        }

        Array array = resultSet.getArray(names[0]);
        @SuppressWarnings("unchecked")
        T javaArray = (T) array.getArray();
        return javaArray;
    }

    @Override
    public void nullSafeSet(PreparedStatement statement, Object value, int index, SessionImplementor session)
            throws HibernateException, SQLException {
        Connection connection = statement.getConnection();
        if (value == null) {
            statement.setNull(index, SQL_TYPES[0]);
        } else {
            @SuppressWarnings("unchecked")
            T castObject = (T) value;
            Array array = connection.createArrayOf("integer", (Object[]) castObject);
            statement.setArray(index, array);
        }
    }

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

    @Override
    public Class<T> returnedClass() {
        return typeParameterClass;
    }

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


}

This will work for Integer array type columns

public class GenericFloatArrayUserType<T extends Serializable> implements UserType {

    protected static final int[] SQL_TYPES = { Types.ARRAY };
    private  Class<T> typeParameterClass;

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

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

    @SuppressWarnings("unchecked")
    @Override
    public Serializable disassemble(Object value) throws HibernateException {
        return (T) this.deepCopy(value);
    }

    @Override
    public boolean equals(Object x, Object y) throws HibernateException {

        if (x == null) {
            return y == null;
        }
        return x.equals(y);
    }

    @Override
    public int hashCode(Object x) throws HibernateException {
        return x.hashCode();
    }

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

    @Override
    public Object nullSafeGet(ResultSet resultSet, String[] names, SessionImplementor session, Object owner)
            throws HibernateException, SQLException {

        if (resultSet.getArray(names[0]) == null) {
            return new Double[0];
        }

        Array array = resultSet.getArray(names[0]);
        @SuppressWarnings("unchecked")
        T javaArray = (T) array.getArray();
        return javaArray;
    }

    @Override
    public void nullSafeSet(PreparedStatement statement, Object value, int index, SessionImplementor session)
            throws HibernateException, SQLException {
        Connection connection = statement.getConnection();
        if (value == null) {
            statement.setNull(index, SQL_TYPES[0]);
        } else {
            @SuppressWarnings("unchecked")
            T castObject = (T) value;
            Array array = connection.createArrayOf("decimal", (Object[]) castObject);
            statement.setArray(index, array);
        }
    }

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

    @Override
    public Class<T> returnedClass() {
        return typeParameterClass;
    }

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


}

Try this for Float data type