1 /*
2 * Copyright (c) 2003, 2020, 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 javax.xml.xpath;
27
28 import java.io.PrintWriter;
29 import java.io.IOException;
30 import java.io.ObjectInputStream;
31 import java.io.ObjectOutputStream;
32 import java.io.ObjectStreamField;
33 import java.io.InvalidClassException;
34
35 /**
36 * {@code XPathException} represents a generic XPath exception.
37 *
38 * @author Norman Walsh
39 * @author Jeff Suttor
40 * @since 1.5
41 */
42 public class XPathException extends Exception {
43 /**
44 * serializable fields
45 */
46 private static final ObjectStreamField[] serialPersistentFields = {
47 new ObjectStreamField( "cause", Throwable.class )
48 };
49
50 /**
51 * Stream Unique Identifier.
52 */
53 private static final long serialVersionUID = -1837080260374986980L;
54
55 /**
56 * Constructs a new {@code XPathException}
57 * with the specified detail {@code message}.
58 *
59 * <p>The {@code cause} is not initialized.
60 *
61 * <p>If {@code message} is {@code null},
62 * then a {@code NullPointerException} is thrown.
63 *
64 * @param message The detail message.
65 *
66 * @throws NullPointerException When {@code message} is
67 * {@code null}.
68 */
69 public XPathException(String message) {
70 super(message);
71 if ( message == null ) {
72 throw new NullPointerException ( "message can't be null");
73 }
74 }
75
76 /**
77 * Constructs a new {@code XPathException}
78 * with the specified {@code cause}.
79 *
80 * <p>If {@code cause} is {@code null},
81 * then a {@code NullPointerException} is thrown.
82 *
83 * @param cause The cause.
84 *
85 * @throws NullPointerException if {@code cause} is {@code null}.
86 */
87 public XPathException(Throwable cause) {
88 super(cause);
89 if ( cause == null ) {
90 throw new NullPointerException ( "cause can't be null");
91 }
92 }
93
94 /**
95 * Get the cause of this XPathException.
96 *
97 * @return Cause of this XPathException.
98 */
99 public Throwable getCause() {
100 return super.getCause();
101 }
102
103 /**
104 * Writes "cause" field to the stream.
105 * The cause is got from the parent class.
106 *
107 * @param out stream used for serialization.
108 * @throws IOException thrown by {@code ObjectOutputStream}
109 *
110 */
111 private void writeObject(ObjectOutputStream out)
112 throws IOException
113 {
114 ObjectOutputStream.PutField fields = out.putFields();
115 fields.put("cause", super.getCause());
116 out.writeFields();
117 }
118
119 /**
120 * Reads the "cause" field from the stream.
121 * And initializes the "cause" if it wasn't
122 * done before.
123 *
124 * @param in stream used for deserialization
125 * @throws IOException thrown by {@code ObjectInputStream}
126 * @throws ClassNotFoundException thrown by {@code ObjectInputStream}
127 */
128 private void readObject(ObjectInputStream in)
129 throws IOException, ClassNotFoundException
130 {
131 ObjectInputStream.GetField fields = in.readFields();
132 Throwable scause = (Throwable) fields.get("cause", null);
133
134 if (super.getCause() == null && scause != null) {
135 try {
136 super.initCause(scause);
137 } catch(IllegalStateException e) {
138 throw new InvalidClassException("Inconsistent state: two causes");
139 }
140 }
141 }
142
143 /**
144 * Print stack trace to specified {@code PrintStream}.
145 *
146 * @param s Print stack trace to this {@code PrintStream}.
147 */
148 public void printStackTrace(java.io.PrintStream s) {
149 if (getCause() != null) {
150 getCause().printStackTrace(s);
151 s.println("--------------- linked to ------------------");
152 }
153
154 super.printStackTrace(s);
155 }
156
157 /**
158 * Print stack trace to {@code System.err}.
159 */
160 public void printStackTrace() {
161 printStackTrace(System.err);
162 }
163
164 /**
165 * Print stack trace to specified {@code PrintWriter}.
166 *
167 * @param s Print stack trace to this {@code PrintWriter}.
168 */
169 public void printStackTrace(PrintWriter s) {
170
171 if (getCause() != null) {
172 getCause().printStackTrace(s);
173 s.println("--------------- linked to ------------------");
174 }
175
176 super.printStackTrace(s);
177 }
178 }