QuantityUserType.java

package dev.morling.demos.usertype;

import java.io.Serializable;
import java.math.BigDecimal;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import java.util.Objects;

import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SharedSessionContractImplementor;
import org.hibernate.type.BigDecimalType;
import org.hibernate.type.StringType;
import org.hibernate.type.Type;
import org.hibernate.usertype.CompositeUserType;
import org.hibernate.usertype.UserType;

/**
  * Use like this:
  *   @Columns(columns = { 
  *      @Column(name = "quantity_amount"), 
  *      @Column(name = "quantity_metric") 
  *   })
  *   @Type(type ="dev.morling.demos.quarkus.QuantityUserType")
  *   public Quantity quantity;
  */
public class QuantityUserType implements CompositeUserType {

    @Override
    public Class returnedClass() {
        return Quantity.class;
    }

    @Override
    public boolean equals(Object x, Object y) throws HibernateException {
        return Objects.equals(x, y);
    }

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

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

        BigDecimal amount = rs.getBigDecimal(names[0]);
        Metric metric = Metric.valueOf(rs.getString(names[1]));

        return new Quantity(amount, metric);
    }

    @Override
    public void nullSafeSet(PreparedStatement st, Object value, int index, SharedSessionContractImplementor session)
            throws HibernateException, SQLException {
        if (value == null) {
            st.setNull(index, Types.NUMERIC);
            st.setNull(index + 1, Types.VARCHAR);
        } else {
            st.setBigDecimal(index, ((Quantity) value).amount);
            st.setString(index + 1, ((Quantity) value).metric.name());
        }
    }

    @Override
    public Object deepCopy(Object value) throws HibernateException {
        return value != null ? new Quantity((Quantity) value) : null;
    }

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

    @Override
    public String[] getPropertyNames() {
        return new String[]{ "amount", "metric" };
    }

    @Override
    public Type[] getPropertyTypes() {
        return new Type[] { BigDecimalType.INSTANCE, StringType.INSTANCE };
    }

    @Override
    public Object getPropertyValue(Object component, int property) throws HibernateException {
        if (property == 0) {
            return ((Quantity)component).amount;
        }
        else {
            return ((Quantity)component).metric;
        }
    }

    @Override
    public void setPropertyValue(Object component, int property, Object value) throws HibernateException {
        if (property == 0) {
            ((Quantity)component).amount = (BigDecimal) value;
        }
        else {
            ((Quantity)component).metric = Metric.valueOf((String) value);
        }
    }

    @Override
    public Serializable disassemble(Object value, SharedSessionContractImplementor session) throws HibernateException {
        throw new UnsupportedOperationException();
    }

    @Override
    public Object assemble(Serializable cached, SharedSessionContractImplementor session, Object owner) {
        throw new UnsupportedOperationException();
    }

    @Override
    public Object replace(Object original, Object target, SharedSessionContractImplementor session, Object owner) {
        return original;
    }
}