J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1995-2004 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.misc; |
| 27 | |
| 28 | /** |
| 29 | * A class to represent a regular expression. Only handles '*'s. |
| 30 | * @author James Gosling |
| 31 | */ |
| 32 | |
| 33 | public class Regexp { |
| 34 | /** if true then the matching process ignores case. */ |
| 35 | public boolean ignoreCase; |
| 36 | |
| 37 | /* |
| 38 | * regular expressions are carved into three regions: a constant string |
| 39 | * prefix, a constant string suffix, and a series of floating strings in |
| 40 | * between. In the input regular expression, they are separated by *s |
| 41 | */ |
| 42 | public String exp; |
| 43 | public String prefix, suffix; |
| 44 | public boolean exact; |
| 45 | public int prefixLen, suffixLen, totalLen; |
| 46 | public String mids[]; |
| 47 | |
| 48 | /** Create a new regular expression object. The regular expression |
| 49 | is a series of constant strings separated by *s. For example: |
| 50 | <dl> |
| 51 | <dt>*.gif <dd>Matches any string that ends in ".gif". |
| 52 | <dt>/tmp/* <dd>Matches any string that starts with "/tmp/". |
| 53 | <dt>/tmp/*.gif <dd>Matches any string that starts with "/tmp/" and ends |
| 54 | with ".gif". |
| 55 | <dt>/tmp/*new*.gif <dd>Matches any string that starts with "/tmp/" |
| 56 | and ends with ".gif" and has "new" somewhere in between. |
| 57 | </dl> |
| 58 | */ |
| 59 | public Regexp (String s) { |
| 60 | exp = s; |
| 61 | int firstst = s.indexOf('*'); |
| 62 | int lastst = s.lastIndexOf('*'); |
| 63 | if (firstst < 0) { |
| 64 | totalLen = s.length(); |
| 65 | exact = true; // no * s |
| 66 | } else { |
| 67 | prefixLen = firstst; |
| 68 | if (firstst == 0) |
| 69 | prefix = null; |
| 70 | else |
| 71 | prefix = s.substring(0, firstst); |
| 72 | suffixLen = s.length() - lastst - 1; |
| 73 | if (suffixLen == 0) |
| 74 | suffix = null; |
| 75 | else |
| 76 | suffix = s.substring(lastst + 1); |
| 77 | int nmids = 0; |
| 78 | int pos = firstst; |
| 79 | while (pos < lastst && pos >= 0) { |
| 80 | nmids++; |
| 81 | pos = s.indexOf('*', pos + 1); |
| 82 | } |
| 83 | totalLen = prefixLen + suffixLen; |
| 84 | if (nmids > 0) { |
| 85 | mids = new String[nmids]; |
| 86 | pos = firstst; |
| 87 | for (int i = 0; i < nmids; i++) { |
| 88 | pos++; |
| 89 | int npos = s.indexOf('*', pos); |
| 90 | if (pos < npos) { |
| 91 | mids[i] = s.substring(pos, npos); |
| 92 | totalLen += mids[i].length(); |
| 93 | } |
| 94 | pos = npos; |
| 95 | } |
| 96 | } |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | /** Returns true iff the String s matches this regular expression. */ |
| 101 | final boolean matches(String s) { |
| 102 | return matches(s, 0, s.length()); |
| 103 | } |
| 104 | |
| 105 | /** Returns true iff the substring of s from offset for len characters |
| 106 | matches this regular expression. */ |
| 107 | boolean matches(String s, int offset, int len) { |
| 108 | if (exact) |
| 109 | return len == totalLen && |
| 110 | exp.regionMatches(ignoreCase, 0, s, offset, len); |
| 111 | if (len < totalLen) |
| 112 | return false; |
| 113 | if (prefixLen > 0 && |
| 114 | !prefix.regionMatches(ignoreCase, |
| 115 | 0, s, offset, prefixLen) |
| 116 | || |
| 117 | suffixLen > 0 && |
| 118 | !suffix.regionMatches(ignoreCase, |
| 119 | 0, s, offset + len - suffixLen, |
| 120 | suffixLen)) |
| 121 | return false; |
| 122 | if (mids == null) |
| 123 | return true; |
| 124 | int nmids = mids.length; |
| 125 | int spos = offset + prefixLen; |
| 126 | int limit = offset+len-suffixLen; |
| 127 | for (int i = 0; i<nmids; i++) { |
| 128 | String ms = mids[i]; |
| 129 | int ml = ms.length(); |
| 130 | while (spos+ml<=limit && |
| 131 | !ms.regionMatches(ignoreCase, |
| 132 | 0, s, spos, ml)) |
| 133 | spos++; |
| 134 | if (spos+ml>limit) |
| 135 | return false; |
| 136 | spos+=ml; |
| 137 | } |
| 138 | return true; |
| 139 | } |
| 140 | |
| 141 | } |