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. */ package org.apache.commons.lang.exception; import java.io.PrintStream; import java.io.PrintWriter; /** * The base class of all errors which can contain other exceptions. * * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a> * @see org.apache.commons.lang.exception.NestableException * @since 1.0 * @version $Id: NestableError.java 491650 2007-01-01 22:00:14Z ggregory $ */ public class NestableError extends Error implements Nestable { /** * Required for serialization support. * * @see java.io.Serializable */ private static final long serialVersionUID = 1L; /** * The helper instance which contains much of the code which we * delegate to. */ protected NestableDelegate delegate = new NestableDelegate(this); /** * Holds the reference to the exception or error that caused * this exception to be thrown. */ private Throwable cause = null; /** * Constructs a new <code>NestableError</code> without specified * detail message. */ public NestableError() { super(); } /** * Constructs a new <code>NestableError</code> with specified * detail message. * * @param msg The error message. */ public NestableError(String msg) { super(msg); } /** * Constructs a new <code>NestableError</code> with specified * nested <code>Throwable</code>. * * @param cause the exception or error that caused this exception to be * thrown */ public NestableError(Throwable cause) { super(); this.cause = cause; } /** * Constructs a new <code>NestableError</code> with specified * detail message and nested <code>Throwable</code>. * * @param msg the error message * @param cause the exception or error that caused this exception to be * thrown */ public NestableError(String msg, Throwable cause) { super(msg); this.cause = cause; } /** * {@inheritDoc} */ public Throwable getCause() { return cause; } /** * Returns the detail message string of this throwable. If it was * created with a null message, returns the following: * (cause==null ? null : cause.toString()). * * @return String message string of the throwable */ public String getMessage() { if (super.getMessage() != null) { return super.getMessage(); } else if (cause != null) { return cause.toString(); } else { return null; } } /** * {@inheritDoc} */ public String getMessage(int index) { if (index == 0) { return super.getMessage(); } return delegate.getMessage(index); } /** * {@inheritDoc} */ public String[] getMessages() { return delegate.getMessages(); } /** * {@inheritDoc} */ public Throwable getThrowable(int index) { return delegate.getThrowable(index); } /** * {@inheritDoc} */ public int getThrowableCount() { return delegate.getThrowableCount(); } /** * {@inheritDoc} */ public Throwable[] getThrowables() { return delegate.getThrowables(); } /** * {@inheritDoc} */ public int indexOfThrowable(Class type) { return delegate.indexOfThrowable(type, 0); } /** * {@inheritDoc} */ public int indexOfThrowable(Class type, int fromIndex) { return delegate.indexOfThrowable(type, fromIndex); } /** * {@inheritDoc} */ public void printStackTrace() { delegate.printStackTrace(); } /** * {@inheritDoc} */ public void printStackTrace(PrintStream out) { delegate.printStackTrace(out); } /** * {@inheritDoc} */ public void printStackTrace(PrintWriter out) { delegate.printStackTrace(out); } /** * {@inheritDoc} */ public final void printPartialStackTrace(PrintWriter out) { super.printStackTrace(out); } }