/*

 * Copyright (c) 1999, 2001, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.naming.directory;

/**

  * This class represents a modification item.

  * It consists of a modification code and an attribute on which to operate.

  *<p>

  * A ModificationItem instance is not synchronized against concurrent

  * multithreaded access. Multiple threads trying to access and modify

  * a single ModificationItem instance should lock the object.

  *

  * @author Rosanna Lee

  * @author Scott Seligman

  * @since 1.3

  */

/*

  *<p>

  * The serialized form of a ModificationItem object consists of the

  * modification op (and int) and the corresponding Attribute.

*/

public class ModificationItem implements java.io.Serializable {

    /**

     * Contains an integer identify the modification

     * to be performed.

     * @serial

     */

    private int mod_op;

    /**

     * Contains the attribute identifying

     * the attribute and/or its value to be applied for the modification.

     * @serial

     */

    private Attribute attr;

    /**

      * Creates a new instance of ModificationItem.

      * @param mod_op Modification to apply.  It must be one of:

      *         DirContext.ADD_ATTRIBUTE

      *         DirContext.REPLACE_ATTRIBUTE

      *         DirContext.REMOVE_ATTRIBUTE

      * @param attr     The non-null attribute to use for modification.

      * @exception IllegalArgumentException If attr is null, or if mod_op is

      *         not one of the ones specified above.

      */

    public ModificationItem(int mod_op, Attribute attr) {

        switch (mod_op) {

        case DirContext.ADD_ATTRIBUTE:

        case DirContext.REPLACE_ATTRIBUTE:

        case DirContext.REMOVE_ATTRIBUTE:

            if (attr == null)

                throw new IllegalArgumentException("Must specify non-null attribute for modification");

            this.mod_op = mod_op;

            this.attr = attr;

            break;

        default:

            throw new IllegalArgumentException("Invalid modification code " + mod_op);

        }

    }

    /**

      * Retrieves the modification code of this modification item.

      * @return The modification code.  It is one of:

      *         DirContext.ADD_ATTRIBUTE

      *         DirContext.REPLACE_ATTRIBUTE

      *         DirContext.REMOVE_ATTRIBUTE

      */

    public int getModificationOp() {

        return mod_op;

    }

    /**

      * Retrieves the attribute associated with this modification item.

      * @return The non-null attribute to use for the modification.

      */

    public Attribute getAttribute() {

        return attr;

    }

    /**

      * Generates the string representation of this modification item,

      * which consists of the modification operation and its related attribute.

      * The string representation is meant for debugging and not to be

      * interpreted programmatically.

      *

      * @return The non-null string representation of this modification item.

      */

    public String toString() {

        switch (mod_op) {

        case DirContext.ADD_ATTRIBUTE:

            return ("Add attribute: " + attr.toString());

        case DirContext.REPLACE_ATTRIBUTE:

            return ("Replace attribute: " + attr.toString());

        case DirContext.REMOVE_ATTRIBUTE:

            return ("Remove attribute: " + attr.toString());

        }

        return "";      // should never happen

    }

    /**

     * Use serialVersionUID from JNDI 1.1.1 for interoperability

     */

    private static final long serialVersionUID = 7573258562534746850L;

}