001/* PatternSyntaxException - Indicates illegal pattern for regular expression.
002   Copyright (C) 2002 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package java.util.regex;
039
040import 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 */
048public 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}