Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.lang.mutable; /** * Provides mutable access to a value. * <p> * <code>Mutable</code> is used as a generic interface to the implementations in this package. * <p> * A typical use case would be to enable a primitive or string to be passed to a method and allow that method to * effectively change the value of the primitive/string. Another use case is to store a frequently changing primitive in * a collection (for example a total in a map) without needing to create new Integer/Long wrapper objects. * * @author Matthew Hawthorne * @since 2.1 * @version $Id: Mutable.java 437554 2006-08-28 06:21:41Z bayard $ */ public interface Mutable { /** * Gets the value of this mutable. * * @return the stored value */ Object getValue(); /** * Sets the value of this mutable. * * @param value * the value to store * @throws NullPointerException * if the object is null and null is invalid * @throws ClassCastException * if the type is invalid */ void setValue(Object value); }