/*

 * Copyright (c) 1999, 2006, 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

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 */

package javax.management;

import java.util.Vector;

/**

 * This class implements of the {@link javax.management.NotificationFilter NotificationFilter}

 * interface for the {@link javax.management.AttributeChangeNotification attribute change notification}.

 * The filtering is performed on the name of the observed attribute.

 * <P>

 * It manages a list of enabled attribute names.

 * A method allows users to enable/disable as many attribute names as required.

 *

 * @since 1.5

 */

public class AttributeChangeNotificationFilter implements NotificationFilter {

    /* Serial version */

    private static final long serialVersionUID = -6347317584796410029L;

    /**

     * @serial {@link Vector} that contains the enabled attribute names.

     *         The default value is an empty vector.

     */

    private Vector<String> enabledAttributes = new Vector<String>();

    /**

     * Invoked before sending the specified notification to the listener.

     * <BR>This filter compares the attribute name of the specified attribute change notification

     * with each enabled attribute name.

     * If the attribute name equals one of the enabled attribute names,

     * the notification must be sent to the listener and this method returns <CODE>true</CODE>.

     *

     * @param notification The attribute change notification to be sent.

     * @return <CODE>true</CODE> if the notification has to be sent to the listener, <CODE>false</CODE> otherwise.

     */

    public synchronized boolean isNotificationEnabled(Notification notification) {

        String type = notification.getType();

        if ((type == null) ||

            (type.equals(AttributeChangeNotification.ATTRIBUTE_CHANGE) == false) ||

            (!(notification instanceof AttributeChangeNotification))) {

            return false;

        }

        String attributeName =

          ((AttributeChangeNotification)notification).getAttributeName();

        return enabledAttributes.contains(attributeName);

    }

    /**

     * Enables all the attribute change notifications the attribute name of which equals

     * the specified name to be sent to the listener.

     * <BR>If the specified name is already in the list of enabled attribute names,

     * this method has no effect.

     *

     * @param name The attribute name.

     * @exception java.lang.IllegalArgumentException The attribute name parameter is null.

     */

    public synchronized void enableAttribute(String name) throws java.lang.IllegalArgumentException {

        if (name == null) {

            throw new java.lang.IllegalArgumentException("The name cannot be null.");

        }

        if (!enabledAttributes.contains(name)) {

            enabledAttributes.addElement(name);

        }

    }

    /**

     * Disables all the attribute change notifications the attribute name of which equals

     * the specified attribute name to be sent to the listener.

     * <BR>If the specified name is not in the list of enabled attribute names,

     * this method has no effect.

     *

     * @param name The attribute name.

     */

    public synchronized void disableAttribute(String name) {

        enabledAttributes.removeElement(name);

    }

    /**

     * Disables all the attribute names.

     */

    public synchronized void disableAllAttributes() {

        enabledAttributes.removeAllElements();

    }

    /**

     * Gets all the enabled attribute names for this filter.

     *

     * @return The list containing all the enabled attribute names.

     */

    public synchronized Vector<String> getEnabledAttributes() {

        return enabledAttributes;

    }

}