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 }