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. */ /** * <p>Operations on boolean primitives and Boolean objects.</p> * * <p>This class tries to handle <code>null</code> input gracefully. * An exception will not be thrown for a <code>null</code> input. * Each method documents its behaviour in more detail.</p> * * @author Stephen Colebourne * @author Matthew Hawthorne * @author Gary Gregory * @since 2.0 * @version $Id: BooleanUtils.java 589050 2007-10-27 05:07:45Z bayard $ */ public class Main { /** * <p>Converts a Boolean to a String returning <code>'on'</code>, * <code>'off'</code>, or <code>null</code>.</p> * * <pre> * BooleanUtils.toStringOnOff(Boolean.TRUE) = "on" * BooleanUtils.toStringOnOff(Boolean.FALSE) = "off" * BooleanUtils.toStringOnOff(null) = null; * </pre> * * @param bool the Boolean to check * @return <code>'on'</code>, <code>'off'</code>, * or <code>null</code> */ public static String toStringOnOff(Boolean bool) { return toString(bool, "on", "off", null); } /** * <p>Converts a Boolean to a String returning one of the input Strings.</p> * * <pre> * BooleanUtils.toString(Boolean.TRUE, "true", "false", null) = "true" * BooleanUtils.toString(Boolean.FALSE, "true", "false", null) = "false" * BooleanUtils.toString(null, "true", "false", null) = null; * </pre> * * @param bool the Boolean to check * @param trueString the String to return if <code>true</code>, * may be <code>null</code> * @param falseString the String to return if <code>false</code>, * may be <code>null</code> * @param nullString the String to return if <code>null</code>, * may be <code>null</code> * @return one of the three input Strings */ public static String toString(Boolean bool, String trueString, String falseString, String nullString) { if (bool == null) { return nullString; } return bool.booleanValue() ? trueString : falseString; } }