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comparison servlet/src/digilib/io/DocuDirectory.java @ 86:997ba69afb81

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New version 1.8b1. With directory and file information cache. With enhanceRGB method for color correction.
author robcast
date Sun, 09 Mar 2003 21:37:27 +0100
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children a398fc09ba71
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85:4e6757e8ccd4 86:997ba69afb81
1 /* DocuDirectory -- Directory of DocuFilesets.
2
3 Digital Image Library servlet components
4
5 Copyright (C) 2003 Robert Casties (robcast@mail.berlios.de)
6
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2 of the License, or (at your
10 option) any later version.
11
12 Please read license.txt for the full details. A copy of the GPL
13 may be found at http://www.gnu.org/copyleft/lgpl.html
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19 * Created on 25.02.2003
20 */
21
22 package digilib.io;
23
24 import java.io.File;
25 import java.util.Arrays;
26 import java.util.Collection;
27 import java.util.Hashtable;
28 import java.util.Vector;
29
30 /**
31 * @author casties
32 */
33 public class DocuDirectory extends Vector {
34
35 // directory object is valid (has been read)
36 private boolean isValid = false;
37 // names of base directories
38 private String[] baseDirNames = null;
39 // directory name (digilib canonical form)
40 private String dirName = null;
41 // default/hires directory
42 private File dir = null;
43 // directory metadata
44 private Hashtable dirMeta = null;
45 // time of last access of this object (not the filesystem)
46 private long objectATime = 0;
47 // time the file system directory was last modified
48 private long dirMTime = 0;
49
50 /*
51 * inherited stuff
52 */
53
54 public DocuDirectory(int initialCapacity, int capacityIncrement) {
55 super(initialCapacity, capacityIncrement);
56 }
57
58 public DocuDirectory(int initialCapacity) {
59 super(initialCapacity);
60 }
61
62 public DocuDirectory(Collection c) {
63 super(c);
64 }
65
66 /*
67 * new stuff
68 */
69
70 /** Constructor with directory path and set of base directories.
71 *
72 * Reads the directory at the given path appended to the base directories.
73 *
74 * @see readDir
75 *
76 * @param path digilib directory path name
77 * @param bd array of base directory names
78 */
79 public DocuDirectory(String path, String[] bd) {
80 super();
81 dirName = path;
82 baseDirNames = bd;
83 readDir();
84 }
85
86 /** Read the directory and fill this object.
87 *
88 * Clears the Vector and (re)reads all files.
89 *
90 * @return boolean the directory exists
91 */
92 public boolean readDir() {
93 // clear directory first
94 clear();
95 isValid = false;
96 // number of base dirs
97 int nb = baseDirNames.length;
98 // array of base dirs
99 File[] dirs = new File[nb];
100 // the first directory has to exist
101 dir = new File(baseDirNames[0] + dirName);
102
103 if (dir.isDirectory()) {
104 // fill array with the remaining directories
105 for (int j = 1; j < nb; j++) {
106 File d = new File(baseDirNames[j] + dirName);
107 if (d.isDirectory()) {
108 dirs[j] = d;
109 }
110 }
111
112 File[] fl = dir.listFiles(new FileOps.ImageFileFilter());
113 if (fl == null) {
114 // not a directory
115 return false;
116 }
117 // number of image files
118 int nf = fl.length;
119 if (nf > 0) {
120 // resize Vector
121 this.ensureCapacity(nf);
122
123 // sort the file names alphabetically and iterate the list
124 Arrays.sort(fl);
125 for (int i = 0; i < nf; i++) {
126 String fn = fl[i].getName();
127 // add the first DocuFile to a new DocuFileset
128 DocuFileset fs = new DocuFileset(nb);
129 fs.add(new DocuFile(fl[i]));
130 // iterate the remaining base directories
131 for (int j = 1; j < nb; j++) {
132 if (dirs[j] == null) {
133 continue;
134 }
135 File f = new File(dirs[j], fn);
136 // if the file exists, add to the DocuFileset
137 if (f.canRead()) {
138 fs.add(new DocuFile(f));
139 }
140 }
141 // add the fileset to our Vector
142 add(fs);
143 fs.setParent(this);
144 }
145 }
146 dirMTime = dir.lastModified();
147 isValid = true;
148 }
149 return isValid;
150
151 }
152
153 /** Check to see if the directory has been modified and reread if necessary.
154 *
155 * @return boolean the directory is valid
156 */
157 public boolean refresh() {
158 if (isValid) {
159 if (dir.lastModified() > dirMTime) {
160 // on-disk modification time is more recent
161 readDir();
162 }
163 touch();
164 }
165 return isValid;
166 }
167
168 /** Read directory metadata.
169 *
170 */
171 public void readMeta() {
172 // check for directory metadata...
173 }
174
175 /** Update access time.
176 *
177 * @return long time of last access.
178 */
179 public long touch() {
180 long t = objectATime;
181 objectATime = System.currentTimeMillis();
182 return t;
183 }
184
185 /** Searches for the file with the name <code>fn</code>.
186 *
187 * Searches the directory for the file with the name <code>fn</code> and returns
188 * its index. Returns -1 if the file cannot be found.
189 *
190 * @param fn filename
191 * @return int index of file <code>fn</code>
192 */
193 public int indexOf(String fn) {
194 // linear search -> worst performance
195 for (int i = 0; i < elementCount; i++) {
196 DocuFileset fs = (DocuFileset) get(i);
197 if (fs.getName().equals(fn)) {
198 return i;
199 }
200 }
201 return -1;
202 }
203
204 /** Finds the DocuFileset with the name <code>fn</code>.
205 *
206 * Searches the directory for the DocuFileset with the name <code>fn</code> and returns
207 * it. Returns null if the file cannot be found.
208 *
209 * @param fn filename
210 * @return DocuFileset
211 */
212 public DocuFileset find(String fn) {
213 int i = indexOf(fn);
214 if (i >= 0) {
215 return (DocuFileset) get(i);
216 }
217 return null;
218 }
219
220 /**
221 * @return String
222 */
223 public String getDirName() {
224 return dirName;
225 }
226
227 /**
228 * @return boolean
229 */
230 public boolean isValid() {
231 return isValid;
232 }
233
234 /**
235 * @return long
236 */
237 public long getAccessTime() {
238 return objectATime;
239 }
240
241 /**
242 * @return Hashtable
243 */
244 public Hashtable getDirMeta() {
245 return dirMeta;
246 }
247
248 /**
249 * @return long
250 */
251 public long getDirMTime() {
252 return dirMTime;
253 }
254
255 /**
256 * Sets the dirMeta.
257 * @param dirMeta The dirMeta to set
258 */
259 public void setDirMeta(Hashtable dirMeta) {
260 this.dirMeta = dirMeta;
261 }
262
263 }