1 /* 2 * Copyright 2001-2005 The Apache Software Foundation 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.apache.commons.mail; 18 19 import java.io.PrintStream; 20 import java.io.PrintWriter; 21 22 /** 23 * Exception thrown when a checked error occurs in commons-email. 24 * <p> 25 * Supports nesting, emulating JDK 1.4 behavior if necessary. 26 * <p> 27 * Adapted from {@link org.apache.commons.collections.FunctorException}. 28 * 29 * @author jakarta-commons 30 * @since 1.0 31 * @version $Id: EmailException.java 279313 2005-09-07 12:41:58Z henning $ 32 */ 33 public class EmailException 34 extends Exception 35 { 36 /** Serializable version identifier */ 37 static final long serialVersionUID = 5550674499282474616L; 38 39 /** 40 * Does JDK support nested exceptions? 41 */ 42 private static final boolean JDK_SUPPORTS_NESTED; 43 44 static 45 { 46 boolean flag = false; 47 48 try 49 { 50 Throwable.class.getDeclaredMethod("getCause", new Class[0]); 51 flag = true; 52 } 53 catch (NoSuchMethodException ex) 54 { 55 flag = false; 56 } 57 58 JDK_SUPPORTS_NESTED = flag; 59 } 60 61 /** 62 * Root cause of the exception 63 */ 64 private final Throwable rootCause; 65 66 /** 67 * Constructs a new <code>EmailException</code> with no 68 * detail message. 69 */ 70 public EmailException() 71 { 72 super(); 73 this.rootCause = null; 74 } 75 76 /** 77 * Constructs a new <code>EmailException</code> with specified 78 * detail message. 79 * 80 * @param msg the error message. 81 */ 82 public EmailException(String msg) 83 { 84 super(msg); 85 this.rootCause = null; 86 } 87 88 /** 89 * Constructs a new <code>EmailException</code> with specified 90 * nested <code>Throwable</code> root cause. 91 * 92 * @param rootCause the exception or error that caused this exception 93 * to be thrown. 94 */ 95 public EmailException(Throwable rootCause) 96 { 97 super(((rootCause == null) ? null : rootCause.getMessage())); 98 this.rootCause = rootCause; 99 } 100 101 /** 102 * Constructs a new <code>EmailException</code> with specified 103 * detail message and nested <code>Throwable</code> root cause. 104 * 105 * @param msg the error message. 106 * @param rootCause the exception or error that caused this exception 107 * to be thrown. 108 */ 109 public EmailException(String msg, Throwable rootCause) 110 { 111 super(msg); 112 this.rootCause = rootCause; 113 } 114 115 /** 116 * Gets the cause of this throwable. 117 * 118 * @return the cause of this throwable, or <code>null</code> 119 */ 120 public Throwable getCause() 121 { 122 return rootCause; 123 } 124 125 /** 126 * Prints the stack trace of this exception to the standard error stream. 127 */ 128 public void printStackTrace() 129 { 130 printStackTrace(System.err); 131 } 132 133 /** 134 * Prints the stack trace of this exception to the specified stream. 135 * 136 * @param out the <code>PrintStream</code> to use for output 137 */ 138 public void printStackTrace(PrintStream out) 139 { 140 synchronized (out) 141 { 142 PrintWriter pw = new PrintWriter(out, false); 143 printStackTrace(pw); 144 145 // Flush the PrintWriter before it's GC'ed. 146 pw.flush(); 147 } 148 } 149 150 /** 151 * Prints the stack trace of this exception to the specified writer. 152 * 153 * @param out the <code>PrintWriter</code> to use for output 154 */ 155 public void printStackTrace(PrintWriter out) 156 { 157 synchronized (out) 158 { 159 super.printStackTrace(out); 160 161 if ((rootCause != null) && (JDK_SUPPORTS_NESTED == false)) 162 { 163 out.print("Caused by: "); 164 rootCause.printStackTrace(out); 165 } 166 } 167 } 168 }