/*
 * Copyright (c) 2008, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Linda DeMichiel - 2.1
//     Linda DeMichiel - 2.0

package jakarta.persistence;

/**
 * Type for query parameter objects.
 * @param <T> the type of the parameter
 *
 * @see Query
 * @see TypedQuery
 *
 * @since 2.0
 */
public interface Parameter<T> {

    /**
     * Return the parameter name, or null if the parameter is
     * not a named parameter or no name has been assigned.
     * @return parameter name
     */
    String getName();

    /**
     * Return the parameter position, or null if the parameter
     * is not a positional parameter. 
     * @return position of parameter
     */
    Integer getPosition();

    /**
     * Return the Java type of the parameter. Values bound to the
     * parameter must be assignable to this type.
     * This method is required to be supported for criteria queries
     * only.   Applications that use this method for Jakarta 
     * Persistence query language queries and native queries will 
     * not be portable.
     * @return the Java type of the parameter
     * @throws IllegalStateException if invoked on a parameter
     *         obtained from a query language 
     *         query or native query when the implementation does 
     *         not support this use
     */
     Class<T> getParameterType();
}

