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1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/XPathSyntaxException.java,v 1.8 2005/04/29 03:05:43 elharo Exp $
3    * $Revision: 1.8 $
4    * $Date: 2005/04/29 03:05:43 $
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 1.8 2005/04/29 03:05:43 elharo Exp $
60   */
61  
62  
63  package org.jaxen;
64  
65  /*** Indicates an error during parsing of an XPath
66   *  expression.
67   *
68   *  @see XPath
69   *
70   *  @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
71   *  @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
72   */
73  public class XPathSyntaxException extends JaxenException
74  {
75      /*** The textual XPath expression */
76      private String xpath;
77  
78      /*** The position of the error */
79      private int    position;
80  
81      /***
82       * Create a new XPathSyntaxException wrapping an existing
83       * <code>org.jaxen.saxpath.XPathSyntaxException</code>.
84       * 
85       * @param e the exception that caused this exception
86       */
87      public XPathSyntaxException(org.jaxen.saxpath.XPathSyntaxException e)
88      {
89          super( e );
90  
91          this.xpath    = e.getXPath();
92          this.position = e.getPosition();
93      }
94  
95      /*** Constructor
96       *
97       *  @param xpath the erroneous XPath expression
98       *  @param position the position of the error
99       *  @param message the error message
100      */
101     public XPathSyntaxException(String xpath,
102                                 int position,
103                                 String message)
104     {
105         super( message );
106 
107         this.xpath    = xpath;
108         this.position = position;
109     }
110 
111     /*** Retrieve the position of the error.
112      *
113      *  @return the position of the error
114      */
115     public int getPosition()
116     {
117         return this.position;
118     }
119 
120     /*** Retrieve the expression containing the error.
121      *
122      *  @return the erroneous expression
123      */
124     public String getXPath()
125     {
126         return this.xpath;
127     }
128 
129     /*** Retrieve a string useful for denoting where
130      *  the error occurred.
131      *
132      *  <p>
133      *  This is a string composed of whitespace and
134      *  a marker at the position (see {@link #getPosition})
135      *  of the error.  This is useful for creating
136      *  friendly multi-line error displays.
137      *  </p>
138      *
139      *  @return the error position marker
140      */
141     public String getPositionMarker()
142     {
143         StringBuffer buf = new StringBuffer();
144 
145         int pos = getPosition();
146 
147         for ( int i = 0 ; i < pos ; ++i )
148         {
149             buf.append(" ");
150         }
151 
152         buf.append("^");
153 
154         return buf.toString();
155         
156     }
157 
158     /*** Retrieve the friendly multi-line error message.
159      *
160      *  <p>
161      *  This returns a multi-line string that contains
162      *  the original erroneous XPath expression with a
163      *  marker underneath indicating exactly where the
164      *  error occurred.
165      *  </p>
166      *
167      *  @return the multi-line error message
168      */
169     public String getMultilineMessage()
170     {
171         StringBuffer buf = new StringBuffer(getMessage());
172         buf.append( "\n" );
173         buf.append( getXPath() );
174         buf.append( "\n" );
175 
176         buf.append( getPositionMarker() );
177 
178         return buf.toString();
179     }
180 }