jdk/src/share/classes/sun/nio/fs/Globs.java
changeset 2057 3acf8e5e2ca0
child 5506 202f599c92aa
equal deleted inserted replaced
2056:115e09b7a004 2057:3acf8e5e2ca0
       
     1 /*
       
     2  * Copyright 2008-2009 Sun Microsystems, Inc.  All Rights Reserved.
       
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
       
     4  *
       
     5  * This code is free software; you can redistribute it and/or modify it
       
     6  * under the terms of the GNU General Public License version 2 only, as
       
     7  * published by the Free Software Foundation.  Sun designates this
       
     8  * particular file as subject to the "Classpath" exception as provided
       
     9  * by Sun in the LICENSE file that accompanied this code.
       
    10  *
       
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
       
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
       
    14  * version 2 for more details (a copy is included in the LICENSE file that
       
    15  * accompanied this code).
       
    16  *
       
    17  * You should have received a copy of the GNU General Public License version
       
    18  * 2 along with this work; if not, write to the Free Software Foundation,
       
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
       
    20  *
       
    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
       
    22  * CA 95054 USA or visit www.sun.com if you need additional information or
       
    23  * have any questions.
       
    24  */
       
    25 
       
    26 package sun.nio.fs;
       
    27 
       
    28 import java.util.regex.PatternSyntaxException;
       
    29 
       
    30 public class Globs {
       
    31     private Globs() { }
       
    32 
       
    33     private static final String regexMetaChars = ".^$+{[]|()";
       
    34     private static final String globMetaChars = "\\*?[{";
       
    35 
       
    36     private static boolean isRegexMeta(char c) {
       
    37         return regexMetaChars.indexOf(c) != -1;
       
    38     }
       
    39 
       
    40     private static boolean isGlobMeta(char c) {
       
    41         return globMetaChars.indexOf(c) != -1;
       
    42     }
       
    43     private static char EOL = 0;  //TBD
       
    44 
       
    45     private static char next(String glob, int i) {
       
    46         if (i < glob.length()) {
       
    47             return glob.charAt(i);
       
    48         }
       
    49         return EOL;
       
    50     }
       
    51 
       
    52     /**
       
    53      * Creates a regex pattern from the given glob expression.
       
    54      *
       
    55      * @throws  PatternSyntaxException
       
    56      */
       
    57     private static String toRegexPattern(String globPattern, boolean isDos) {
       
    58         boolean inGroup = false;
       
    59         StringBuilder regex = new StringBuilder("^");
       
    60 
       
    61         int i = 0;
       
    62         while (i < globPattern.length()) {
       
    63             char c = globPattern.charAt(i++);
       
    64             switch (c) {
       
    65                 case '\\':
       
    66                     // escape special characters
       
    67                     if (i == globPattern.length()) {
       
    68                         throw new PatternSyntaxException("No character to escape",
       
    69                                 globPattern, i - 1);
       
    70                     }
       
    71                     char next = globPattern.charAt(i++);
       
    72                     if (isGlobMeta(next) || isRegexMeta(next)) {
       
    73                         regex.append('\\');
       
    74                     }
       
    75                     regex.append(next);
       
    76                     break;
       
    77                 case '/':
       
    78                     if (isDos) {
       
    79                         regex.append("\\\\");
       
    80                     } else {
       
    81                         regex.append(c);
       
    82                     }
       
    83                     break;
       
    84                 case '[':
       
    85                     // don't match name separator in class
       
    86                     if (isDos) {
       
    87                         regex.append("[[^\\\\]&&[");
       
    88                     } else {
       
    89                         regex.append("[[^/]&&[");
       
    90                     }
       
    91                     if (next(globPattern, i) == '^') {
       
    92                         // escape the regex negation char if it appears
       
    93                         regex.append("\\^");
       
    94                         i++;
       
    95                     } else {
       
    96                         // negation
       
    97                         if (next(globPattern, i) == '!') {
       
    98                             regex.append('^');
       
    99                             i++;
       
   100                         }
       
   101                         // hyphen allowed at start
       
   102                         if (next(globPattern, i) == '-') {
       
   103                             regex.append('-');
       
   104                             i++;
       
   105                         }
       
   106                     }
       
   107                     boolean hasRangeStart = false;
       
   108                     char last = 0;
       
   109                     while (i < globPattern.length()) {
       
   110                         c = globPattern.charAt(i++);
       
   111                         if (c == ']') {
       
   112                             break;
       
   113                         }
       
   114                         if (c == '/' || (isDos && c == '\\')) {
       
   115                             throw new PatternSyntaxException("Explicit 'name separator' in class",
       
   116                                     globPattern, i - 1);
       
   117                         }
       
   118                         // TBD: how to specify ']' in a class?
       
   119                         if (c == '\\' || c == '[' ||
       
   120                                 c == '&' && next(globPattern, i) == '&') {
       
   121                             // escape '\', '[' or "&&" for regex class
       
   122                             regex.append('\\');
       
   123                         }
       
   124                         regex.append(c);
       
   125 
       
   126                         if (c == '-') {
       
   127                             if (!hasRangeStart) {
       
   128                                 throw new PatternSyntaxException("Invalid range",
       
   129                                         globPattern, i - 1);
       
   130                             }
       
   131                             if ((c = next(globPattern, i++)) == EOL || c == ']') {
       
   132                                 break;
       
   133                             }
       
   134                             if (c < last) {
       
   135                                 throw new PatternSyntaxException("Invalid range",
       
   136                                         globPattern, i - 3);
       
   137                             }
       
   138                             regex.append(c);
       
   139                             hasRangeStart = false;
       
   140                         } else {
       
   141                             hasRangeStart = true;
       
   142                             last = c;
       
   143                         }
       
   144                     }
       
   145                     if (c != ']') {
       
   146                         throw new PatternSyntaxException("Missing ']", globPattern, i - 1);
       
   147                     }
       
   148                     regex.append("]]");
       
   149                     break;
       
   150                 case '{':
       
   151                     if (inGroup) {
       
   152                         throw new PatternSyntaxException("Cannot nest groups",
       
   153                                 globPattern, i - 1);
       
   154                     }
       
   155                     regex.append("(?:(?:");
       
   156                     inGroup = true;
       
   157                     break;
       
   158                 case '}':
       
   159                     if (inGroup) {
       
   160                         regex.append("))");
       
   161                         inGroup = false;
       
   162                     } else {
       
   163                         regex.append('}');
       
   164                     }
       
   165                     break;
       
   166                 case ',':
       
   167                     if (inGroup) {
       
   168                         regex.append(")|(?:");
       
   169                     } else {
       
   170                         regex.append(',');
       
   171                     }
       
   172                     break;
       
   173                 case '*':
       
   174                     if (next(globPattern, i) == '*') {
       
   175                         // crosses directory boundaries
       
   176                         regex.append(".*");
       
   177                         i++;
       
   178                     } else {
       
   179                         // within directory boundary
       
   180                         if (isDos) {
       
   181                             regex.append("[^\\\\]*");
       
   182                         } else {
       
   183                             regex.append("[^/]*");
       
   184                         }
       
   185                     }
       
   186                     break;
       
   187                 case '?':
       
   188                    if (isDos) {
       
   189                        regex.append("[^\\\\]");
       
   190                    } else {
       
   191                        regex.append("[^/]");
       
   192                    }
       
   193                    break;
       
   194 
       
   195                 default:
       
   196                     if (isRegexMeta(c)) {
       
   197                         regex.append('\\');
       
   198                     }
       
   199                     regex.append(c);
       
   200             }
       
   201         }
       
   202 
       
   203         if (inGroup) {
       
   204             throw new PatternSyntaxException("Missing '}", globPattern, i - 1);
       
   205         }
       
   206 
       
   207         return regex.append('$').toString();
       
   208     }
       
   209 
       
   210     static String toUnixRegexPattern(String globPattern) {
       
   211         return toRegexPattern(globPattern, false);
       
   212     }
       
   213 
       
   214     static String toWindowsRegexPattern(String globPattern) {
       
   215         return toRegexPattern(globPattern, true);
       
   216     }
       
   217 }