001    /* PatternSyntaxException - Indicates illegal pattern for regular expression.
002       Copyright (C) 2002 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package java.util.regex;
039    
040    import gnu.java.lang.CPStringBuilder;
041    
042    /**
043     * Indicates illegal pattern for regular expression.
044     * Includes state to inspect the pattern and what and where the expression
045     * was not valid regular expression.
046     * @since 1.4
047     */
048    public class PatternSyntaxException extends IllegalArgumentException
049    {
050      private static final long serialVersionUID = -3864639126226059218L;
051    
052      /**
053       * Human readable escription of the syntax error.
054       */
055      private final String desc;
056    
057      /**
058       * The original pattern that contained the syntax error.
059       */
060      private final String pattern;
061      
062      /**
063       * Index of the first character in the String that was probably invalid,
064       * or -1 when unknown.
065       */
066      private final int index;
067    
068      /**
069       * Creates a new PatternSyntaxException.
070       *
071       * @param description Human readable escription of the syntax error.
072       * @param pattern The original pattern that contained the syntax error.
073       * @param index Index of the first character in the String that was
074       *        probably invalid, or -1 when unknown.
075       */
076      public PatternSyntaxException(String description,
077                                    String pattern,
078                                    int index)
079      {
080        super(description);
081        this.desc = description;
082        this.pattern = pattern;
083        this.index = index;
084      }
085    
086      /**
087       * Returns a human readable escription of the syntax error.
088       */
089      public String getDescription()
090      {
091        return desc;
092      }
093    
094      /**
095       * Returns the original pattern that contained the syntax error.
096       */
097      public String getPattern()
098      {
099        return pattern;
100      }
101    
102      /**
103       * Returns the index of the first character in the String that was probably
104       * invalid, or -1 when unknown.
105       */
106      public int getIndex()
107      {
108        return index;
109      }
110    
111      /**
112       * Returns a string containing a line with the description, a line with
113       * the original pattern and a line indicating with a ^ which character is
114       * probably the first invalid character in the pattern if the index is not
115       * negative.
116       */
117      public String getMessage()
118      {
119        String lineSep = System.getProperty("line.separator");
120        CPStringBuilder sb = new CPStringBuilder(desc);
121        sb.append(lineSep);
122        sb.append('\t');
123        sb.append(pattern);
124        if (index != -1)
125          {
126            sb.append(lineSep);
127            sb.append('\t');
128            for (int i=0; i<index; i++)
129              sb.append(' ');
130            sb.append('^');
131          }
132        return sb.toString();
133      }
134    
135    }