View Javadoc

1   /*
2    * $Header$
3    * $Revision: 1161 $
4    * $Date: 2006-06-03 13:36:00 -0700 (Sat, 03 Jun 2006) $
5    *
6    * ====================================================================
7    *
8    * Copyright 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 are
13   * met:
14   * 
15   *   * Redistributions of source code must retain the above copyright
16   *     notice, this list of conditions and the following disclaimer.
17   * 
18   *   * Redistributions in binary form must reproduce the above copyright
19   *     notice, this list of conditions and the following disclaimer in the
20   *     documentation and/or other materials provided with the distribution.
21   * 
22   *   * Neither the name of the Jaxen Project nor the names of its
23   *     contributors may be used to endorse or promote products derived 
24   *     from this software without specific prior written permission.
25   * 
26   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27   * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29   * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30   * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37   *
38   * ====================================================================
39   * This software consists of voluntary contributions made by many 
40   * individuals on behalf of the Jaxen Project and was originally 
41   * created by bob mcwhirter <bob@werken.com> and 
42   * James Strachan <jstrachan@apache.org>.  For more information on the 
43   * Jaxen Project, please see <http://www.jaxen.org/>.
44   * 
45   * $Id: XPathSyntaxException.java 1161 2006-06-03 20:36:00Z elharo $
46   */
47  
48  
49  package org.jaxen;
50  
51  /** Indicates an error during parsing of an XPath expression.
52   *
53   *  @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
54   *  @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
55   */
56  public class XPathSyntaxException extends JaxenException
57  {
58      /**
59       * 
60       */
61      private static final long serialVersionUID = 1980601567207604059L;
62  
63      /** The textual XPath expression */
64      private String xpath;
65  
66      /** The position of the error */
67      private int    position;
68  
69      /**
70       * Create a new XPathSyntaxException wrapping an existing
71       * <code>org.jaxen.saxpath.XPathSyntaxException</code>.
72       * 
73       * @param e the exception that caused this exception
74       */
75      public XPathSyntaxException(org.jaxen.saxpath.XPathSyntaxException e)
76      {
77          super( e );
78  
79          this.xpath    = e.getXPath();
80          this.position = e.getPosition();
81      }
82  
83      /** Constructor
84       *
85       *  @param xpath the erroneous XPath expression
86       *  @param position the position of the error
87       *  @param message the error message
88       */
89      public XPathSyntaxException(String xpath,
90                                  int position,
91                                  String message)
92      {
93          super( message );
94  
95          this.xpath    = xpath;
96          this.position = position;
97      }
98  
99      /** Retrieve the position of the error.
100      *
101      *  @return the position of the error
102      */
103     public int getPosition()
104     {
105         return this.position;
106     }
107 
108     /** Retrieve the expression containing the error.
109      *
110      *  @return the erroneous expression
111      */
112     public String getXPath()
113     {
114         return this.xpath;
115     }
116 
117     /** Retrieve a string useful for denoting where
118      *  the error occurred.
119      *
120      *  <p>
121      *  This is a string composed of whitespace and
122      *  a marker at the position (see {@link #getPosition})
123      *  of the error.  This is useful for creating
124      *  friendly multi-line error displays.
125      *  </p>
126      *
127      *  @return the error position marker
128      */
129     public String getPositionMarker()
130     {
131         StringBuffer buf = new StringBuffer();
132 
133         int pos = getPosition();
134 
135         for ( int i = 0 ; i < pos ; ++i )
136         {
137             buf.append(" ");
138         }
139 
140         buf.append("^");
141 
142         return buf.toString();
143         
144     }
145 
146     /** Retrieve the friendly multi-line error message.
147      *
148      *  <p>
149      *  This returns a multi-line string that contains
150      *  the original erroneous XPath expression with a
151      *  marker underneath indicating exactly where the
152      *  error occurred.
153      *  </p>
154      *
155      *  @return the multi-line error message
156      */
157     public String getMultilineMessage()
158     {
159         StringBuffer buf = new StringBuffer(getMessage());
160         buf.append( "\n" );
161         buf.append( getXPath() );
162         buf.append( "\n" );
163 
164         buf.append( getPositionMarker() );
165 
166         return buf.toString();
167     }
168 }