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 char primitives and Character 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 * @since 2.1 * @version $Id: CharUtils.java 437554 2006-08-28 06:21:41Z bayard $ */ public class Main { //-------------------------------------------------------------------------- /** * <p>Converts the string to the unicode format '\u0020'.</p> * * <p>This format is the Java source code format.</p> * * <pre> * CharUtils.unicodeEscaped(' ') = "\u0020" * CharUtils.unicodeEscaped('A') = "\u0041" * </pre> * * @param ch the character to convert * @return the escaped unicode string */ public static String unicodeEscaped(char ch) { if (ch < 0x10) { return "\\u000" + Integer.toHexString(ch); } else if (ch < 0x100) { return "\\u00" + Integer.toHexString(ch); } else if (ch < 0x1000) { return "\\u0" + Integer.toHexString(ch); } return "\\u" + Integer.toHexString(ch); } /** * <p>Converts the string to the unicode format '\u0020'.</p> * * <p>This format is the Java source code format.</p> * * <p>If <code>null</code> is passed in, <code>null</code> will be returned.</p> * * <pre> * CharUtils.unicodeEscaped(null) = null * CharUtils.unicodeEscaped(' ') = "\u0020" * CharUtils.unicodeEscaped('A') = "\u0041" * </pre> * * @param ch the character to convert, may be null * @return the escaped unicode string, null if null input */ public static String unicodeEscaped(Character ch) { if (ch == null) { return null; } return unicodeEscaped(ch.charValue()); } }