1 /*
2  * Copyright (c) 2003, 2017, 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
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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
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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
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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     private static final ObjectStreamField[] serialPersistentFields = {
45         new ObjectStreamField( "cause", Throwable.class )
46     };
47 
48     /**
49      * Stream Unique Identifier.
50      */
51     private static final long serialVersionUID = -1837080260374986980L;
52 
53     /**
54      * Constructs a new {@code XPathException}
55      * with the specified detail {@code message}.
56      *
57      * <p>The {@code cause} is not initialized.
58      *
59      * <p>If {@code message} is {@code null},
60      * then a {@code NullPointerException} is thrown.
61      *
62      * @param message The detail message.
63      *
64      * @throws NullPointerException When {@code message} is
65      *   {@code null}.
66      */
XPathException(String message)67     public XPathException(String message) {
68         super(message);
69         if ( message == null ) {
70             throw new NullPointerException ( "message can't be null");
71         }
72     }
73 
74     /**
75      * Constructs a new {@code XPathException}
76      * with the specified {@code cause}.
77      *
78      * <p>If {@code cause} is {@code null},
79      * then a {@code NullPointerException} is thrown.
80      *
81      * @param cause The cause.
82      *
83      * @throws NullPointerException if {@code cause} is {@code null}.
84      */
XPathException(Throwable cause)85     public XPathException(Throwable cause) {
86         super(cause);
87         if ( cause == null ) {
88             throw new NullPointerException ( "cause can't be null");
89         }
90     }
91 
92     /**
93      * Get the cause of this XPathException.
94      *
95      * @return Cause of this XPathException.
96      */
getCause()97     public Throwable getCause() {
98         return super.getCause();
99     }
100 
101     /**
102      * Writes "cause" field to the stream.
103      * The cause is got from the parent class.
104      *
105      * @param out stream used for serialization.
106      * @throws IOException thrown by {@code ObjectOutputStream}
107      *
108      */
writeObject(ObjectOutputStream out)109     private void writeObject(ObjectOutputStream out)
110             throws IOException
111     {
112         ObjectOutputStream.PutField fields = out.putFields();
113         fields.put("cause", super.getCause());
114         out.writeFields();
115     }
116 
117     /**
118      * Reads the "cause" field from the stream.
119      * And initializes the "cause" if it wasn't
120      * done before.
121      *
122      * @param in stream used for deserialization
123      * @throws IOException thrown by {@code ObjectInputStream}
124      * @throws ClassNotFoundException  thrown by {@code ObjectInputStream}
125      */
readObject(ObjectInputStream in)126     private void readObject(ObjectInputStream in)
127             throws IOException, ClassNotFoundException
128     {
129         ObjectInputStream.GetField fields = in.readFields();
130         Throwable scause = (Throwable) fields.get("cause", null);
131 
132         if (super.getCause() == null && scause != null) {
133             try {
134                 super.initCause(scause);
135             } catch(IllegalStateException e) {
136                 throw new InvalidClassException("Inconsistent state: two causes");
137             }
138         }
139     }
140 
141     /**
142      * Print stack trace to specified {@code PrintStream}.
143      *
144      * @param s Print stack trace to this {@code PrintStream}.
145      */
printStackTrace(java.io.PrintStream s)146     public void printStackTrace(java.io.PrintStream s) {
147         if (getCause() != null) {
148             getCause().printStackTrace(s);
149           s.println("--------------- linked to ------------------");
150         }
151 
152         super.printStackTrace(s);
153     }
154 
155     /**
156      * Print stack trace to {@code System.err}.
157      */
printStackTrace()158     public void printStackTrace() {
159         printStackTrace(System.err);
160     }
161 
162     /**
163      * Print stack trace to specified {@code PrintWriter}.
164      *
165      * @param s Print stack trace to this {@code PrintWriter}.
166      */
printStackTrace(PrintWriter s)167     public void printStackTrace(PrintWriter s) {
168 
169         if (getCause() != null) {
170             getCause().printStackTrace(s);
171           s.println("--------------- linked to ------------------");
172         }
173 
174         super.printStackTrace(s);
175     }
176 }
177