org.intermine.objectstore.query.QueryObjectReference Maven / Gradle / Ivy

Go to download
package org.intermine.objectstore.query;

/*
 * Copyright (C) 2002-2022 FlyMine
 *
 * This code may be freely distributed and modified under the
 * terms of the GNU Lesser General Public Licence.  This should
 * be distributed with the code.  See the LICENSE file for more
 * information or http://www.gnu.org/copyleft/lesser.html.
 *
 */

import java.lang.reflect.Method;
import java.util.Collection;

import org.intermine.metadata.TypeUtil;
import org.intermine.model.InterMineObject;

/**
 * Represents a field of a QueryClass that is a business object
 *
 * @author Mark Woodbridge
 * @author Richard Smith
 * @author Matthew Wakeling
 */
public class QueryObjectReference extends QueryReference implements QueryOrderable
{
    /**
     * Constructs a QueryObjectReference representing the specified field of a QueryClass
     *
     * @param qc the QueryClass
     * @param fieldName the name of the relevant field
     * @throws NullPointerException if the field name is null
     * @throws IllegalArgumentException if the field is not a reference, or does not exist
     */
    public QueryObjectReference(QueryClass qc, String fieldName) {
        if (fieldName == null) {
            throw new NullPointerException("Field name parameter is null");
        }
        Method field = TypeUtil.getGetter(qc.getType(), fieldName);
        if (field == null) {
            throw new IllegalArgumentException("Field " + fieldName + " not found in "
                                           + qc.getType());
        }
        if (Collection.class.isAssignableFrom(field.getReturnType())) {
            throw new IllegalArgumentException("Field " + fieldName + " is a collection type");
        }
        if (!InterMineObject.class.isAssignableFrom(field.getReturnType())) {
            throw new IllegalArgumentException("Field " + fieldName + " is not a separate database "
                    + "object");
        }
        this.qc = qc;
        this.fieldName = fieldName;
        this.type = field.getReturnType();
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    @Override
    public Class getType() {
        return (Class) type;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toString() {
        return qc.toString() + "." +  fieldName;
    }
}