1 | /* This file is part of the project "Hilbert II" - http://www.qedeq.org |
2 | * |
3 | * Copyright 2000-2014, Michael Meyling <mime@qedeq.org>. |
4 | * |
5 | * "Hilbert II" is free software; you can redistribute |
6 | * it and/or modify it under the terms of the GNU General Public |
7 | * License as published by the Free Software Foundation; either |
8 | * version 2 of the License, or (at your option) any later version. |
9 | * |
10 | * This program is distributed in the hope that it will be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
13 | * GNU General Public License for more details. |
14 | */ |
15 | |
16 | package org.qedeq.base.io; |
17 | |
18 | import java.util.ArrayList; |
19 | import java.util.List; |
20 | |
21 | import org.apache.commons.lang.ArrayUtils; |
22 | import org.qedeq.base.utility.EqualsUtility; |
23 | import org.qedeq.base.utility.StringUtility; |
24 | |
25 | |
26 | /** |
27 | * A file path that leads to a directory or file and is absolute or relative. |
28 | * This abstraction of a file location was done to create relative file paths. |
29 | * This class makes some assumptions about a file path: |
30 | * "/" is the directory separator, "/" is also the root directory and ".." specifies |
31 | * the parent directory. "." is the current directory. |
32 | * A directory path must end with a "/" if a path ends not with a "/" it will be a file path |
33 | * (but the empty path "" is a directory). |
34 | * |
35 | * @author Michael Meyling |
36 | */ |
37 | public final class Path { |
38 | |
39 | /** Directories that build up the path. If this is an absolute path the first |
40 | * name is empty. */ |
41 | private final String[] path; |
42 | |
43 | /** File name. */ |
44 | private final String name; |
45 | |
46 | /** |
47 | * Create file with given path and name. |
48 | * |
49 | * @param filePath Path to file with "/" as directory name separator. Relative directories |
50 | * are removed from the file path if possible. Must not be |
51 | * <code>null</code>. Might be "" this is called the <em>empty path</em>. |
52 | */ |
53 | public Path(final String filePath) { |
54 | final String[] p = StringUtility.split(filePath, "/"); |
55 | name = p[p.length - 1]; |
56 | final String[] p2 = new String[p.length - 1]; |
57 | System.arraycopy(p, 0, p2, 0, p2.length); |
58 | path = removeRelativeDirs(p2); |
59 | } |
60 | |
61 | /** |
62 | * Create file with given path and name. Relative directories are removed from |
63 | * the file path if possible. |
64 | * |
65 | * @param dirPath Directory path to file with "/" as directory name separator. |
66 | * This value can end with a "/" but it must not be <code>null</code>. |
67 | * @param fileName File name. It should not contain "/" but this is not checked. |
68 | */ |
69 | public Path(final String dirPath, final String fileName) { |
70 | this((dirPath.endsWith("/") ? StringUtility.split(dirPath.substring(0, |
71 | dirPath.length() - 1), "/") : StringUtility.split(dirPath, "/")), fileName); |
72 | } |
73 | |
74 | /** |
75 | * Create file with given path and name. Relative directories are removed |
76 | * from the file path if possible. |
77 | * |
78 | * @param dirNames Directory names. If this is an absolute path the first |
79 | * name is empty. Must not be <code>null</code>. |
80 | * @param fileName File name. It should not contain "/" but this is not checked. |
81 | */ |
82 | public Path(final String[] dirNames, final String fileName) { |
83 | path = removeRelativeDirs(dirNames); |
84 | name = (fileName != null ? fileName : ""); |
85 | } |
86 | |
87 | /** |
88 | * Create new file path relative to given one. If the original path or <code>filePath</code> |
89 | * is a relative path it will return <code>filePath</code>. |
90 | * |
91 | * @param filePath Path to file relative to <code>this</code>. |
92 | * @return Relative file path (if possible). |
93 | */ |
94 | public Path createRelative(final String filePath) { |
95 | final Path to = new Path(filePath); |
96 | if (isRelative()) { |
97 | // if from is relative, then we don't need to think further |
98 | return to; |
99 | } |
100 | if (to.isRelative()) { |
101 | return to; |
102 | } |
103 | // both are absolute so we try to navigate within the file system |
104 | // to get a relative path |
105 | int max = 0; |
106 | while (max < path.length && max < to.path.length) { |
107 | if (!"..".equals(path[max]) && EqualsUtility.equals(path[max], to.path[max])) { |
108 | max++; |
109 | } else { |
110 | break; |
111 | } |
112 | } |
113 | final String[] r = new String[path.length - max + to.path.length - max]; |
114 | for (int i = max; i < path.length; i++) { |
115 | r[i - max] = ".."; |
116 | } |
117 | for (int i = max; i < to.path.length; i++) { |
118 | r[i - max + path.length - max] = to.path[i]; |
119 | } |
120 | return new Path(r, to.name); |
121 | } |
122 | |
123 | /** |
124 | * Describes this path a directory? |
125 | * |
126 | * @return Is directory? |
127 | */ |
128 | public boolean isDirectory() { |
129 | return name.length() == 0; |
130 | } |
131 | |
132 | /** |
133 | * Describes this path a file (and not a directory)? |
134 | * |
135 | * @return Is this a path to a file? |
136 | */ |
137 | public boolean isFile() { |
138 | return !isDirectory(); |
139 | } |
140 | |
141 | /** |
142 | * Is this an absolute path? If first path directory name is empty or ends with ":" |
143 | * (MS windows tribute) this is the case. |
144 | * |
145 | * @return Is absolute path? |
146 | */ |
147 | public boolean isAbsolute() { |
148 | return path.length > 0 && (path[0].length() == 0 || path[0].endsWith(":")); |
149 | } |
150 | |
151 | /** |
152 | * Is this a relative path? |
153 | * |
154 | * @return Is this a relative path? |
155 | */ |
156 | public boolean isRelative() { |
157 | return !isAbsolute(); |
158 | } |
159 | |
160 | /** |
161 | * Get filename. Is "" if this is a pure directory path. |
162 | * |
163 | * @return File name. Might be "" but not <code>null</code>. |
164 | */ |
165 | public String getFileName() { |
166 | return name; |
167 | } |
168 | |
169 | /** |
170 | * Get directory of this path. This might be a relative or absolute |
171 | * path and ends with "/". (Only the empty path "" has no ending "/".) |
172 | * |
173 | * @return Directory this path points to. Will end with "/" if this is not |
174 | * an empty path. |
175 | */ |
176 | public String getDirectory() { |
177 | StringBuffer result = new StringBuffer(256); |
178 | for (int i = 0; i < path.length; i++) { |
179 | result.append(path[i]).append("/"); |
180 | } |
181 | return result.toString(); |
182 | } |
183 | |
184 | /** |
185 | * Remove ".." and "." directories out of path if possible. |
186 | * |
187 | * @param dirNames Directories that build up the path. |
188 | * @return Directories that build up the same path. |
189 | */ |
190 | private String[] removeRelativeDirs(final String[] dirNames) { |
191 | List d = new ArrayList(); |
192 | for (int i = 0; i < dirNames.length; i++) { |
193 | d.add(dirNames[i]); |
194 | } |
195 | for (int i = 0; i < d.size(); ) { |
196 | if (i > 0 && "..".equals(d.get(i)) && !"".equals(d.get(i - 1)) |
197 | && !"..".equals(d.get(i - 1))) { |
198 | d.remove(i - 1); |
199 | d.remove(i - 1); |
200 | i--; |
201 | } else if (".".equals(d.get(i))) { |
202 | d.remove(i); |
203 | } else { |
204 | i++; |
205 | } |
206 | } |
207 | return (String[]) d.toArray(ArrayUtils.EMPTY_STRING_ARRAY); |
208 | } |
209 | |
210 | public String toString() { |
211 | StringBuffer result = new StringBuffer(256); |
212 | for (int i = 0; i < path.length; i++) { |
213 | result.append(path[i]).append("/"); |
214 | } |
215 | result.append(name); |
216 | return result.toString(); |
217 | } |
218 | |
219 | public boolean equals(final Object obj) { |
220 | if (!(obj instanceof Path)) { |
221 | return false; |
222 | } |
223 | final Path other = (Path) obj; |
224 | return EqualsUtility.equals(path, other.path) && name.equals(other.name); |
225 | } |
226 | |
227 | public int hashCode() { |
228 | return toString().hashCode(); |
229 | } |
230 | |
231 | } |
232 | |