Java tutorial
/* * * This file is part of the iText (R) project. Copyright (c) 1998-2019 iText Group NV * Authors: Bruno Lowagie, Paulo Soares, et al. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License version 3 * as published by the Free Software Foundation with the addition of the * following permission added to Section 15 as permitted in Section 7(a): * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT * OF THIRD PARTY RIGHTS * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Affero General Public License for more details. * You should have received a copy of the GNU Affero General Public License * along with this program; if not, see http://www.gnu.org/licenses or write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA, 02110-1301 USA, or download the license from the following URL: * http://itextpdf.com/terms-of-use/ * * The interactive user interfaces in modified source and object code versions * of this program must display Appropriate Legal Notices, as required under * Section 5 of the GNU Affero General Public License. * * In accordance with Section 7(b) of the GNU Affero General Public License, * a covered work must retain the producer line in every PDF that is created * or manipulated using iText. * * You can be released from the requirements of the license by purchasing * a commercial license. Buying such a license is mandatory as soon as you * develop commercial activities involving the iText software without * disclosing the source code of your own applications. * These activities include: offering paid services to customers as an ASP, * serving PDFs on the fly in a web application, shipping iText with a closed * source product. * * For more information, please contact iText Software Corp. at this * address: sales@itextpdf.com */ /* * The original version of this class was published in an article by professor Heinz Kabutz. * Read http://www.javaspecialists.eu/archive/Issue033.html * "This material from The Java(tm) Specialists' Newsletter by Maximum Solutions (South Africa). * Please contact Maximum Solutions for more information." * * Copyright (C) 2001 Dr. Heinz M. Kabutz * Permission was granted by Dr. Kabutz to use this source code in iText. */ package com.itextpdf.text; /** * The ExceptionConverter changes a checked exception into an * unchecked exception. */ public class ExceptionConverter extends RuntimeException { private static final long serialVersionUID = 8657630363395849399L; /** we keep a handle to the wrapped exception */ private Exception ex; /** prefix for the exception */ private String prefix; /** * Construct a RuntimeException based on another Exception * @param ex the exception that has to be turned into a RuntimeException */ public ExceptionConverter(Exception ex) { super(ex); this.ex = ex; prefix = (ex instanceof RuntimeException) ? "" : "ExceptionConverter: "; } /** * Convert an Exception into an unchecked exception. Return the exception if it is * already an unchecked exception or return an ExceptionConverter wrapper otherwise * * @param ex the exception to convert * @return an unchecked exception * @since 2.1.6 */ public static final RuntimeException convertException(Exception ex) { if (ex instanceof RuntimeException) { return (RuntimeException) ex; } return new ExceptionConverter(ex); } /** * and allow the user of ExceptionConverter to get a handle to it. * @return the original exception */ public Exception getException() { return ex; } /** * We print the message of the checked exception * @return message of the original exception */ public String getMessage() { return ex.getMessage(); } /** * and make sure we also produce a localized version * @return localized version of the message */ public String getLocalizedMessage() { return ex.getLocalizedMessage(); } /** * The toString() is changed to be prefixed with ExceptionConverter * @return String version of the exception */ public String toString() { return prefix + ex; } /** we have to override this as well */ public void printStackTrace() { printStackTrace(System.err); } /** * here we prefix, with s.print(), not s.println(), the stack * trace with "ExceptionConverter:" * @param s */ public void printStackTrace(java.io.PrintStream s) { synchronized (s) { s.print(prefix); ex.printStackTrace(s); } } /** * Again, we prefix the stack trace with "ExceptionConverter:" * @param s */ public void printStackTrace(java.io.PrintWriter s) { synchronized (s) { s.print(prefix); ex.printStackTrace(s); } } /** * requests to fill in the stack trace we will have to ignore. * We can't throw an exception here, because this method * is called by the constructor of Throwable * @return a Throwable */ public Throwable fillInStackTrace() { return this; } }