/*

  * Copyright (c) 1999, 2008, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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  */

 package java.util.regex;

 /**

  * Unchecked exception thrown to indicate a syntax error in a

  * regular-expression pattern.

  *

  * @author  unascribed

  * @since 1.4

  * @spec JSR-51

  */

 public class PatternSyntaxException

     extends IllegalArgumentException

 {

     private static final long serialVersionUID = -3864639126226059218L;

     private final String desc;

     private final String pattern;

     private final int index;

     /**

      * Constructs a new instance of this class.

      *

      * @param  desc

      *         A description of the error

      *

      * @param  regex

      *         The erroneous pattern

      *

      * @param  index

      *         The approximate index in the pattern of the error,

      *         or <tt>-1</tt> if the index is not known

      */

     public PatternSyntaxException(String desc, String regex, int index) {

         this.desc = desc;

         this.pattern = regex;

         this.index = index;

     }

     /**

      * Retrieves the error index.

      *

      * @return  The approximate index in the pattern of the error,

      *         or <tt>-1</tt> if the index is not known

      */

     public int getIndex() {

         return index;

     }

     /**

      * Retrieves the description of the error.

      *

      * @return  The description of the error

      */

     public String getDescription() {

         return desc;

     }

     /**

      * Retrieves the erroneous regular-expression pattern.

      *

      * @return  The erroneous pattern

      */

     public String getPattern() {

         return pattern;

     }

     private static final String nl = System.lineSeparator();

     /**

      * Returns a multi-line string containing the description of the syntax

      * error and its index, the erroneous regular-expression pattern, and a

      * visual indication of the error index within the pattern.

      *

      * @return  The full detail message

      */

     public String getMessage() {

         StringBuffer sb = new StringBuffer();

         sb.append(desc);

         if (index >= 0) {

             sb.append(" near index ");

             sb.append(index);

         }

         sb.append(nl);

         sb.append(pattern);

         if (index >= 0) {

             sb.append(nl);

             for (int i = 0; i < index; i++) sb.append(' ');

             sb.append('^');

         }

         return sb.toString();

     }

 }