1 /*
   2  * Copyright (c) 1996, 2000, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang;
  27 
  28 /**
  29  * Signals that an unexpected exception has occurred in a static initializer.
  30  * An <code>ExceptionInInitializerError</code> is thrown to indicate that an
  31  * exception occurred during evaluation of a static initializer or the
  32  * initializer for a static variable.
  33  *
  34  * <p>As of release 1.4, this exception has been retrofitted to conform to
  35  * the general purpose exception-chaining mechanism.  The "saved throwable
  36  * object" that may be provided at construction time and accessed via
  37  * the {@link #getException()} method is now known as the <i>cause</i>,
  38  * and may be accessed via the {@link Throwable#getCause()} method, as well
  39  * as the aforementioned "legacy method."
  40  *
  41  * @author  Frank Yellin
  42  * @since   1.1
  43  */
  44 public class ExceptionInInitializerError extends LinkageError {
  45     /**
  46      * Use serialVersionUID from JDK 1.1.X for interoperability
  47      */
  48     private static final long serialVersionUID = 1521711792217232256L;
  49 
  50     /**
  51      * This field holds the exception if the
  52      * ExceptionInInitializerError(Throwable thrown) constructor was
  53      * used to instantiate the object
  54      *
  55      * @serial
  56      *
  57      */
  58     private Throwable exception;
  59 
  60     /**
  61      * Constructs an <code>ExceptionInInitializerError</code> with
  62      * <code>null</code> as its detail message string and with no saved
  63      * throwable object.
  64      * A detail message is a String that describes this particular exception.
  65      */
  66     public ExceptionInInitializerError() {
  67         initCause(null);  // Disallow subsequent initCause
  68     }
  69 
  70     /**
  71      * Constructs a new <code>ExceptionInInitializerError</code> class by
  72      * saving a reference to the <code>Throwable</code> object thrown for
  73      * later retrieval by the {@link #getException()} method. The detail
  74      * message string is set to <code>null</code>.
  75      *
  76      * @param thrown The exception thrown
  77      */
  78     public ExceptionInInitializerError(Throwable thrown) {
  79         initCause(null);  // Disallow subsequent initCause
  80         this.exception = thrown;
  81     }
  82 
  83     /**
  84      * Constructs an ExceptionInInitializerError with the specified detail
  85      * message string.  A detail message is a String that describes this
  86      * particular exception. The detail message string is saved for later
  87      * retrieval by the {@link Throwable#getMessage()} method. There is no
  88      * saved throwable object.
  89      *
  90      *
  91      * @param s the detail message
  92      */
  93     public ExceptionInInitializerError(String s) {
  94         super(s);
  95         initCause(null);  // Disallow subsequent initCause
  96     }
  97 
  98     /**
  99      * Returns the exception that occurred during a static initialization that
 100      * caused this error to be created.
 101      *
 102      * <p>This method predates the general-purpose exception chaining facility.
 103      * The {@link Throwable#getCause()} method is now the preferred means of
 104      * obtaining this information.
 105      *
 106      * @return the saved throwable object of this
 107      *         <code>ExceptionInInitializerError</code>, or <code>null</code>
 108      *         if this <code>ExceptionInInitializerError</code> has no saved
 109      *         throwable object.
 110      */
 111     public Throwable getException() {
 112         return exception;
 113     }
 114 
 115     /**
 116      * Returns the cause of this error (the exception that occurred
 117      * during a static initialization that caused this error to be created).
 118      *
 119      * @return  the cause of this error or <code>null</code> if the
 120      *          cause is nonexistent or unknown.
 121      * @since   1.4
 122      */
 123     public Throwable getCause() {
 124         return exception;
 125     }
 126 }