Java tutorial
/* * Copyright (c) 1994, 2016, 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 java.util; /** * A class can implement the {@code Observer} interface when it * wants to be informed of changes in observable objects. * * @author Chris Warth * @see java.util.Observable * @since 1.0 * * @deprecated * This interface has been deprecated. See the {@link Observable} * class for further information. */ @Deprecated(since = "9") public interface Observer { /** * This method is called whenever the observed object is changed. An * application calls an {@code Observable} object's * {@code notifyObservers} method to have all the object's * observers notified of the change. * * @param o the observable object. * @param arg an argument passed to the {@code notifyObservers} * method. */ void update(Observable o, Object arg); }