PgArrayExpression.java

package net.kaleidos.hibernate.criterion.array;

import net.kaleidos.hibernate.usertype.ArrayType;
import net.kaleidos.hibernate.utils.PgArrayUtils;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.annotations.common.util.StringHelper;
import org.hibernate.criterion.CriteriaQuery;
import org.hibernate.criterion.Criterion;
import org.hibernate.engine.spi.TypedValue;
import org.hibernate.type.CustomType;
import org.hibernate.type.Type;

/**
 * Constrains a property in an array
 */
public class PgArrayExpression implements Criterion {

    private static final long serialVersionUID = 2872183637309166619L;

    private final String propertyName;
    private final Object value;
    private final String op;

    protected PgArrayExpression(String propertyName, Object value, String op) {
        this.propertyName = propertyName;
        this.value = value;
        this.op = op;
    }

    @Override
    public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
        ArrayType arrayType = checkAndGetArrayType(criteria, criteriaQuery);

        String postgresArrayType = PgArrayUtils.getNativeSqlTypeRead(arrayType.getTypeClass(), arrayType.isStringCaseInsensitive());

        return StringHelper.join(
                " and ",
                StringHelper.suffix(criteriaQuery.findColumns(propertyName, criteria), " " + op + " CAST(? as " + postgresArrayType + ")")
        );
    }

    @Override
    public TypedValue[] getTypedValues(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
        ArrayType arrayType = checkAndGetArrayType(criteria, criteriaQuery);

        Object[] arrValue;
        if (arrayType.getTypeClass().isEnum()) {
            arrValue = PgArrayUtils.getValueAsArrayOfType(
                    value,
                    Integer.class,
                    new PgArrayUtils.MapFunction() {
                        @SuppressWarnings("rawtypes")
                        public Object map(Object o) {
                            try {
                                return ((Enum) o).ordinal();
                            } catch (ClassCastException e) {
                                throw new HibernateException("Unable to cast object " + o + " to Enum.");
                            }
                        }
                    }
            );
        } else {
            arrValue = PgArrayUtils.getValueAsArrayOfType(value, arrayType.getTypeClass());
        }

        return new TypedValue[]{
                criteriaQuery.getTypedValue(criteria, propertyName, arrValue)
        };
    }

    private ArrayType checkAndGetArrayType(Criteria criteria, CriteriaQuery criteriaQuery) {
        Type propertyType = criteriaQuery.getType(criteria, propertyName);

        if (!(propertyType instanceof CustomType) || !(((CustomType) propertyType).getUserType() instanceof ArrayType)) {
            throw new HibernateException("Property is not an instance of the postgres type ArrayType. Type is: " + propertyType.getClass());
        }

        return (ArrayType) ((CustomType) propertyType).getUserType();
    }
}