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 import java.io.IOException;
29 import java.io.ObjectInputStream;
30 import java.io.ObjectOutputStream;
31 import java.io.ObjectStreamField;
32
33 /**
34 * Signals that an unexpected exception has occurred in a static initializer.
35 * An <code>ExceptionInInitializerError</code> is thrown to indicate that an
36 * exception occurred during evaluation of a static initializer or the
37 * initializer for a static variable.
38 *
39 * <p>As of release 1.4, this exception has been retrofitted to conform to
40 * the general purpose exception-chaining mechanism. The "saved throwable
41 * object" that may be provided at construction time and accessed via
42 * the {@link #getException()} method is now known as the <i>cause</i>,
43 * and may be accessed via the {@link Throwable#getCause()} method, as well
44 * as the aforementioned "legacy method."
45 *
46 * @author Frank Yellin
47 * @since 1.1
48 */
49 public class ExceptionInInitializerError extends LinkageError {
50 /**
51 * Use serialVersionUID from JDK 1.1.X for interoperability
52 */
53 private static final long serialVersionUID = 1521711792217232256L;
54
55 /**
56 * Constructs an <code>ExceptionInInitializerError</code> with
57 * <code>null</code> as its detail message string and with no saved
58 * throwable object.
59 * A detail message is a String that describes this particular exception.
60 */
61 public ExceptionInInitializerError() {
62 initCause(null); // Disallow subsequent initCause
63 }
64
65 /**
66 * Constructs a new <code>ExceptionInInitializerError</code> class by
67 * saving a reference to the <code>Throwable</code> object thrown for
68 * later retrieval by the {@link #getException()} method. The detail
69 * message string is set to <code>null</code>.
70 *
71 * @param thrown The exception thrown
72 */
73 public ExceptionInInitializerError(Throwable thrown) {
74 super(null, thrown); // Disallow subsequent initCause
75 }
76
77 /**
78 * Constructs an {@code ExceptionInInitializerError} with the specified detail
79 * message string. A detail message is a String that describes this
80 * particular exception. The detail message string is saved for later
81 * retrieval by the {@link Throwable#getMessage()} method. There is no
82 * saved throwable object.
83 *
84 * @param s the detail message
85 */
86 public ExceptionInInitializerError(String s) {
87 super(s, null); // Disallow subsequent initCause
88 }
89
90 /**
91 * Returns the exception that occurred during a static initialization that
92 * caused this error to be created.
93 *
94 * <p>This method predates the general-purpose exception chaining facility.
95 * The {@link Throwable#getCause()} method is now the preferred means of
96 * obtaining this information.
97 *
98 * @return the saved throwable object of this
99 * <code>ExceptionInInitializerError</code>, or <code>null</code>
100 * if this <code>ExceptionInInitializerError</code> has no saved
101 * throwable object.
102 */
103 public Throwable getException() {
104 return super.getCause();
105 }
106
107 /**
108 * Serializable fields for ExceptionInInitializerError.
109 *
110 * @serialField exception Throwable
111 */
112 private static final ObjectStreamField[] serialPersistentFields = {
113 new ObjectStreamField("exception", Throwable.class)
114 };
115
116 /*
117 * Reconstitutes the ExceptionInInitializerError instance from a stream
118 * and initialize the cause properly when deserializing from an older
119 * version.
120 *
121 * The getException and getCause method returns the private "exception"
122 * field in the older implementation and ExceptionInInitializerError::cause
123 * was set to null.
124 */
125 private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
126 ObjectInputStream.GetField fields = s.readFields();
127 Throwable exception = (Throwable) fields.get("exception", null);
128 if (exception != null) {
129 setCause(exception);
130 }
131 }
132
133 /*
134 * To maintain compatibility with older implementation, write a serial
135 * "exception" field with the cause as the value.
136 */
137 private void writeObject(ObjectOutputStream out) throws IOException {
138 ObjectOutputStream.PutField fields = out.putFields();
139 fields.put("exception", super.getCause());
140 out.writeFields();
141 }
142
143 }