| 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 | |