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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   JDK1.1
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 }