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1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/XPathSyntaxException.java,v 1.10 2005/09/25 11:41:31 elharo Exp $
3    * $Revision: 1.10 $
4    * $Date: 2005/09/25 11:41:31 $
5    *
6    * ====================================================================
7    *
8    * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
9    * All rights reserved.
10   *
11   * Redistribution and use in source and binary forms, with or without
12   * modification, are permitted provided that the following conditions
13   * are met:
14   * 
15   * 1. Redistributions of source code must retain the above copyright
16   *    notice, this list of conditions, and the following disclaimer.
17   *
18   * 2. Redistributions in binary form must reproduce the above copyright
19   *    notice, this list of conditions, and the disclaimer that follows 
20   *    these conditions in the documentation and/or other materials 
21   *    provided with the distribution.
22   *
23   * 3. The name "Jaxen" must not be used to endorse or promote products
24   *    derived from this software without prior written permission.  For
25   *    written permission, please contact license@jaxen.org.
26   * 
27   * 4. Products derived from this software may not be called "Jaxen", nor
28   *    may "Jaxen" appear in their name, without prior written permission
29   *    from the Jaxen Project Management (pm@jaxen.org).
30   * 
31   * In addition, we request (but do not require) that you include in the 
32   * end-user documentation provided with the redistribution and/or in the 
33   * software itself an acknowledgement equivalent to the following:
34   *     "This product includes software developed by the
35   *      Jaxen Project <http://www.jaxen.org/>."
36   * Alternatively, the acknowledgment may be graphical using the logos 
37   * available at http://www.jaxen.org/
38   *
39   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
40   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42   * DISCLAIMED.  IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
43   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
45   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
46   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
47   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
48   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
49   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50   * SUCH DAMAGE.
51   *
52   * ====================================================================
53   * This software consists of voluntary contributions made by many 
54   * individuals on behalf of the Jaxen Project and was originally 
55   * created by bob mcwhirter <bob@werken.com> and 
56   * James Strachan <jstrachan@apache.org>.  For more information on the 
57   * Jaxen Project, please see <http://www.jaxen.org/>.
58   * 
59   * $Id: XPathSyntaxException.java,v 1.10 2005/09/25 11:41:31 elharo Exp $
60   */
61  
62  
63  package org.jaxen;
64  
65  /*** Indicates an error during parsing of an XPath expression.
66   *
67   *  @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
68   *  @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
69   */
70  public class XPathSyntaxException extends JaxenException
71  {
72      /*** The textual XPath expression */
73      private String xpath;
74  
75      /*** The position of the error */
76      private int    position;
77  
78      /***
79       * Create a new XPathSyntaxException wrapping an existing
80       * <code>org.jaxen.saxpath.XPathSyntaxException</code>.
81       * 
82       * @param e the exception that caused this exception
83       */
84      public XPathSyntaxException(org.jaxen.saxpath.XPathSyntaxException e)
85      {
86          super( e );
87  
88          this.xpath    = e.getXPath();
89          this.position = e.getPosition();
90      }
91  
92      /*** Constructor
93       *
94       *  @param xpath the erroneous XPath expression
95       *  @param position the position of the error
96       *  @param message the error message
97       */
98      public XPathSyntaxException(String xpath,
99                                  int position,
100                                 String message)
101     {
102         super( message );
103 
104         this.xpath    = xpath;
105         this.position = position;
106     }
107 
108     /*** Retrieve the position of the error.
109      *
110      *  @return the position of the error
111      */
112     public int getPosition()
113     {
114         return this.position;
115     }
116 
117     /*** Retrieve the expression containing the error.
118      *
119      *  @return the erroneous expression
120      */
121     public String getXPath()
122     {
123         return this.xpath;
124     }
125 
126     /*** Retrieve a string useful for denoting where
127      *  the error occurred.
128      *
129      *  <p>
130      *  This is a string composed of whitespace and
131      *  a marker at the position (see {@link #getPosition})
132      *  of the error.  This is useful for creating
133      *  friendly multi-line error displays.
134      *  </p>
135      *
136      *  @return the error position marker
137      */
138     public String getPositionMarker()
139     {
140         StringBuffer buf = new StringBuffer();
141 
142         int pos = getPosition();
143 
144         for ( int i = 0 ; i < pos ; ++i )
145         {
146             buf.append(" ");
147         }
148 
149         buf.append("^");
150 
151         return buf.toString();
152         
153     }
154 
155     /*** Retrieve the friendly multi-line error message.
156      *
157      *  <p>
158      *  This returns a multi-line string that contains
159      *  the original erroneous XPath expression with a
160      *  marker underneath indicating exactly where the
161      *  error occurred.
162      *  </p>
163      *
164      *  @return the multi-line error message
165      */
166     public String getMultilineMessage()
167     {
168         StringBuffer buf = new StringBuffer(getMessage());
169         buf.append( "\n" );
170         buf.append( getXPath() );
171         buf.append( "\n" );
172 
173         buf.append( getPositionMarker() );
174 
175         return buf.toString();
176     }
177 }