    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017    package org.apache.commons.lang;
    018
    019    /**
    020     * <p>Thrown to indicate that an argument was <code>null</code> and should
    021     * not have been.
    022     * This exception supplements the standard <code>IllegalArgumentException</code>
    023     * by providing a more semantically rich description of the problem.</p>
    024     *
    025     * <p><code>NullArgumentException</code> represents the case where a method takes
    026     * in a parameter that must not be <code>null</code>.
    027     * Some coding standards would use <code>NullPointerException</code> for this case,
    028     * others will use <code>IllegalArgumentException</code>.
    029     * Thus this exception would be used in place of
    030     * <code>IllegalArgumentException</code>, yet it still extends it.</p>
    031     *
    032     * <pre>
    033     * public void foo(String str) {
    034     *   if (str == null) {
    035     *     throw new NullArgumentException("str");
    036     *   }
    037     *   // do something with the string
    038     * }
    039     * </pre>
    040     *
    041     * @author Apache Software Foundation
    042     * @author Matthew Hawthorne
    043     * @since 2.0
    044     * @version $Id: NullArgumentException.java 905636 2010-02-02 14:03:32Z niallp $
    045     */
    046    public class NullArgumentException extends IllegalArgumentException {
    047
    048        /**
    049         * Required for serialization support.
    050         *
    051         * @see java.io.Serializable
    052         */
    053        private static final long serialVersionUID = 1174360235354917591L;
    054
    055        /**
    056         * <p>Instantiates with the given argument name.</p>
    057         *
    058         * @param argName  the name of the argument that was <code>null</code>.
    059         */
    060        public NullArgumentException(String argName) {
    061            super((argName == null ? "Argument" : argName) + " must not be null.");
    062        }
    063
    064    }