Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright (c) 1997-2017 Oracle and/or its affiliates. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common Development * and Distribution License("CDDL") (collectively, the "License"). You * may not use this file except in compliance with the License. You can * obtain a copy of the License at * https://oss.oracle.com/licenses/CDDL+GPL-1.1 * or LICENSE.txt. See the License for the specific * language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each * file and include the License file at LICENSE.txt. * * GPL Classpath Exception: * Oracle designates this particular file as subject to the "Classpath" * exception as provided by Oracle in the GPL Version 2 section of the License * file that accompanied this code. * * Modifications: * If applicable, add the following below the License Header, with the fields * enclosed by brackets [] replaced by your own identifying information: * "Portions Copyright [year] [name of copyright owner]" * * Contributor(s): * If you wish your version of this file to be governed by only the CDDL or * only the GPL Version 2, indicate your decision by adding "[Contributor] * elects to include this software in this distribution under the [CDDL or GPL * Version 2] license." If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ package javax.mail; import java.lang.*; /** * The base class for all exceptions thrown by the Messaging classes * * @author John Mani * @author Bill Shannon */ public class MessagingException extends Exception { /** * The next exception in the chain. * * @serial */ private Exception next; private static final long serialVersionUID = -7569192289819959253L; /** * Constructs a MessagingException with no detail message. */ public MessagingException() { super(); initCause(null); // prevent anyone else from setting it } /** * Constructs a MessagingException with the specified detail message. * * @param s the detail message */ public MessagingException(String s) { super(s); initCause(null); // prevent anyone else from setting it } /** * Constructs a MessagingException with the specified * Exception and detail message. The specified exception is chained * to this exception. * * @param s the detail message * @param e the embedded exception * @see #getNextException * @see #setNextException * @see #getCause */ public MessagingException(String s, Exception e) { super(s); next = e; initCause(null); // prevent anyone else from setting it } /** * Get the next exception chained to this one. If the * next exception is a MessagingException, the chain * may extend further. * * @return next Exception, null if none. */ public synchronized Exception getNextException() { return next; } /** * Overrides the <code>getCause</code> method of <code>Throwable</code> * to return the next exception in the chain of nested exceptions. * * @return next Exception, null if none. */ @Override public synchronized Throwable getCause() { return next; } /** * Add an exception to the end of the chain. If the end * is <strong>not</strong> a MessagingException, this * exception cannot be added to the end. * * @param ex the new end of the Exception chain * @return <code>true</code> if this Exception * was added, <code>false</code> otherwise. */ public synchronized boolean setNextException(Exception ex) { Exception theEnd = this; while (theEnd instanceof MessagingException && ((MessagingException) theEnd).next != null) { theEnd = ((MessagingException) theEnd).next; } // If the end is a MessagingException, we can add this // exception to the chain. if (theEnd instanceof MessagingException) { ((MessagingException) theEnd).next = ex; return true; } else return false; } /** * Override toString method to provide information on * nested exceptions. */ @Override public synchronized String toString() { String s = super.toString(); Exception n = next; if (n == null) return s; StringBuilder sb = new StringBuilder(s == null ? "" : s); while (n != null) { sb.append(";\n nested exception is:\n\t"); if (n instanceof MessagingException) { MessagingException mex = (MessagingException) n; sb.append(mex.superToString()); n = mex.next; } else { sb.append(n.toString()); n = null; } } return sb.toString(); } /** * Return the "toString" information for this exception, * without any information on nested exceptions. */ private final String superToString() { return super.toString(); } }