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comparison software/eXist/mpdl-modules/src/de/mpg/mpiwg/berlin/mpdl/util/FileUtil.java @ 0:408254cf2f1d

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author Josef Willenborg <jwillenborg@mpiwg-berlin.mpg.de>
date Wed, 24 Nov 2010 17:24:23 +0100
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1 package de.mpg.mpiwg.berlin.mpdl.util;
2
3 import java.io.BufferedInputStream;
4 import java.io.BufferedOutputStream;
5 import java.io.File;
6 import java.io.FileInputStream;
7 import java.io.FileNotFoundException;
8 import java.io.FileOutputStream;
9 import java.io.FilenameFilter;
10 import java.io.IOException;
11 import java.io.InputStream;
12 import java.io.OutputStream;
13 import java.io.RandomAccessFile;
14 import java.net.MalformedURLException;
15 import java.net.URI;
16 import java.net.URL;
17 import java.net.URLConnection;
18 import java.util.ArrayList;
19 import java.util.List;
20
21 import de.mpg.mpiwg.berlin.mpdl.exception.ApplicationException;
22
23 public class FileUtil {
24 private static FileUtil instance;
25
26 public static FileUtil getInstance() throws ApplicationException {
27 if (instance == null) {
28 instance = new FileUtil();
29 }
30 return instance;
31 }
32
33 public void createDirectory(String dir) {
34 File destLocalDirectory = new File(dir);
35 destLocalDirectory.mkdirs();
36 }
37
38 public void deleteDirectory(String dir) {
39 File destLocalDirectory = new File(dir);
40 // directory with all files and subdirectories is deleted
41 deleteDirectory(destLocalDirectory);
42 }
43
44 /**
45 * Deletes all files and subdirectories under dir. No exception is thrown
46 * if dir (or one of its children) does nor exist.
47 * @dir dir the directory to be deleted
48 * @return true if all deletions were successful. If a deletion fails, the method stops attempting to delete and returns false.
49 */
50 public boolean deleteDirectory(File dir) {
51 if (dir.isDirectory()) {
52 String[] children = dir.list();
53 for (int i=0; i<children.length; i++) {
54 boolean success = deleteDirectory(new File(dir, children[i]));
55 if (!success) {
56 return false; // if one of the files or subdirectories could not be deleted return false but recursively works further
57 }
58 }
59 }
60 // The directory is now empty so delete it
61 return dir.delete();
62 }
63
64 public void deleteFile(String fileName) {
65 File destLocalFile = new File(fileName);
66 // if destLocalFile does not exist nothing happens and no exception is thrown
67 // if destLocalFile is a directory and is not empty an exception is thrown (should not happen because this method is called only by remove)
68 destLocalFile.delete();
69 }
70
71 /**
72 * List all files in a directory
73 * @param dirStr
74 * @return
75 */
76 public File[] getFiles(String dirStr) {
77 File dir = new File(dirStr);
78 File[] dirFiles = dir.listFiles();
79 return dirFiles;
80 }
81
82 /**
83 *
84 * @param dirStr
85 * @param filter
86 * @return
87 */
88 public File[] getFiles(String dirStr, FilenameFilter filter) {
89 File dir = new File(dirStr);
90 File[] dirFiles = dir.listFiles(filter);
91 return dirFiles;
92 }
93
94 /**
95 * Write all bytes into destFile. If directory for that destFile does not exist
96 * it creates this directory including parent directories.
97 * @param bytes bytes to write
98 * @param destFileName destination file name
99 * @throws Exception
100 */
101 public void saveFile(byte[] bytes, String destFileName) throws ApplicationException {
102 OutputStream out = null;
103 try {
104 if (bytes == null)
105 return; // do nothing
106 File destFile = new File(destFileName);
107 File destDir = new File(destFile.getParent());
108 if (! destDir.exists()) {
109 destDir.mkdirs(); // create the directory including parent directories which do not exist
110 }
111 out = new BufferedOutputStream(new FileOutputStream(destFile));
112 out.write(bytes, 0, bytes.length);
113 out.flush();
114 } catch (FileNotFoundException e) {
115 throw new ApplicationException(e);
116 } catch (IOException e) {
117 throw new ApplicationException(e);
118 } finally {
119 try {
120 if (out != null)
121 out.close();
122 } catch (Exception e) {
123 // nothing: always close the stream at the end of the method
124 }
125 }
126 }
127
128 public void copyFile(String srcFileName, String destFileName) throws ApplicationException {
129 InputStream in = null;
130 OutputStream out = null;
131 try {
132 File srcFile = new File(srcFileName);
133 if (! srcFile.exists())
134 return; // do nothing
135 File destFile = new File(destFileName);
136 File destDir = new File(destFile.getParent());
137 if (! destDir.exists()) {
138 destDir.mkdirs(); // create the directory including parent directories which do not exist
139 }
140 in = new BufferedInputStream(new FileInputStream(srcFile));
141 out = new BufferedOutputStream(new FileOutputStream(destFile));
142 int bufLen = 20000*1024;
143 byte[] buf = new byte[bufLen];
144 int len = 0;
145 while ((len = in.read(buf)) > 0) {
146 out.write(buf, 0, len);
147 }
148 out.flush(); // buffered content is flushed to file
149 } catch (FileNotFoundException e) {
150 throw new ApplicationException(e);
151 } catch (IOException e) {
152 throw new ApplicationException(e);
153 } finally {
154 try {
155 if (in != null)
156 in.close();
157 if (out != null)
158 out.close();
159 } catch (Exception e) {
160 // nothing: always close the stream at the end of the method
161 }
162 }
163 }
164
165 public void saveUrlToLocalFile(URL srcUrl, String destFileName) throws ApplicationException {
166 BufferedInputStream in = null;
167 BufferedOutputStream out = null;
168 try {
169 /* wenn ein Zugriff mit "http:" gemacht wird, wird die XML Deklaration (<?xml version="1.0"?>) nicht ausgelesen
170 * beim Zugriff mit "file;" ist das anders
171 * evtl. wieder einbauen, um die Deklaration manuell zu schreiben
172 URLConnection urlConn = srcUrl.openConnection();
173 String contentTypeStr = urlConn.getContentType();
174 String contentEncodingStr = urlConn.getContentEncoding();
175 boolean contentTypeXml = false;
176 if (contentTypeStr != null) {
177 contentTypeStr = contentTypeStr.toLowerCase();
178 if (contentTypeStr.indexOf("application/xml") != -1 || contentTypeStr.indexOf("text/xml") != -1)
179 contentTypeXml = true;
180 }
181 */
182 InputStream inputStream = srcUrl.openStream();
183 in = new BufferedInputStream(inputStream);
184 File outputFile = new File(destFileName);
185 File outputDir = new File(outputFile.getParent());
186 if (! outputDir.exists()) {
187 outputDir.mkdirs(); // create the directory including parent directories which do not exist
188 }
189 out = new BufferedOutputStream(new FileOutputStream(outputFile));
190 int bufLen = 1000*1024;
191 byte[] buf = new byte[bufLen];
192 int len = 0;
193 /*
194 if (contentTypeXml) {
195 String xmlDecl = "<?xml version=\"1.0\"?>\n";
196 out.write(xmlDecl.getBytes("utf-8"));
197 }
198 */
199 while ((len = in.read(buf)) > 0) {
200 out.write(buf, 0, len);
201 out.flush();
202 }
203 } catch (MalformedURLException e) {
204 throw new ApplicationException(e);
205 } catch (IOException e) {
206 throw new ApplicationException(e);
207 } finally {
208 try {
209 if (in != null)
210 in.close();
211 if (out != null)
212 out.close();
213 } catch (Exception e) {
214 // nothing: always close the stream at the end of the method
215 }
216 }
217 }
218
219 public void saveInputStreamToLocalFile(InputStream srcInputStream, String destFileName) throws ApplicationException {
220 BufferedInputStream in = null;
221 BufferedOutputStream out = null;
222 try {
223 in = new BufferedInputStream(srcInputStream);
224 File outputFile = new File(destFileName);
225 File outputDir = new File(outputFile.getParent());
226 if (! outputDir.exists()) {
227 outputDir.mkdirs(); // create the directory including parent directories which do not exist
228 }
229 out = new BufferedOutputStream(new FileOutputStream(outputFile));
230 int bufLen = 1000*1024;
231 byte[] buf = new byte[bufLen];
232 int len = 0;
233 while ((len = in.read(buf)) > 0) {
234 out.write(buf, 0, len);
235 out.flush();
236 }
237 } catch (MalformedURLException e) {
238 throw new ApplicationException(e);
239 } catch (IOException e) {
240 throw new ApplicationException(e);
241 } finally {
242 try {
243 if (in != null)
244 in.close();
245 if (out != null)
246 out.close();
247 } catch (Exception e) {
248 // nothing: always close the stream at the end of the method
249 }
250 }
251 }
252
253 public void deleteLastNBytes(File file, int countBytes) throws ApplicationException {
254 try {
255 RandomAccessFile raf = new RandomAccessFile(file, "rw");
256 long length = raf.length();
257 raf.setLength(length - countBytes);
258 raf.close();
259 } catch (IOException e) {
260 throw new ApplicationException(e);
261 }
262 }
263
264 public void testFile(String fileName) throws ApplicationException {
265 File file = new File(fileName);
266 boolean fileExists = file.exists();
267 if (! fileExists) {
268 throw new ApplicationException("File: " + fileName + " does not exist");
269 }
270 }
271
272 /**
273 * Reads a chunk of data of an input stream.
274 * Does not close the stream until last bytes are read
275 * @in in the input stream to be read
276 * @chunkSize chunkSize length of the chunk which is read
277 * @return byte[] of bytes read
278 */
279 public byte[] readBytes(InputStream in, int chunkSize) throws ApplicationException {
280 byte[] resultBytes = new byte[chunkSize];
281 try {
282 int len = in.read(resultBytes, 0, chunkSize);
283 if (len == -1) {
284 try { in.close(); } catch (Exception e) { } // close the stream if end of file is reached
285 resultBytes = null;
286 } else if (len < chunkSize && len != chunkSize) { // if read chunk is last chunk of the file it delivers this chunk
287 byte[] tmp = new byte[len];
288 System.arraycopy(resultBytes, 0, tmp, 0, len);
289 resultBytes = tmp;
290 }
291 } catch (FileNotFoundException e) {
292 throw new ApplicationException(e);
293 } catch (IOException e) {
294 throw new ApplicationException(e);
295 }
296 return resultBytes;
297 }
298
299 /**
300 * Reads a file storing intermediate data into an array.
301 * @file file the file to be read
302 * @return byte[] of file content
303 */
304 public byte[] readBytes(String fileName) throws ApplicationException {
305 InputStream in = null;
306 byte[] out = new byte[0];
307 try {
308 in = new BufferedInputStream(new FileInputStream(fileName));
309 // the length of a buffer can vary
310 int bufLen = 20000*1024;
311 byte[] buf = new byte[bufLen];
312 byte[] tmp = null;
313 int len = 0;
314 while((len = in.read(buf, 0, bufLen)) != -1) {
315 // extend array
316 tmp = new byte[out.length + len];
317 System.arraycopy(out, 0, tmp, 0, out.length);
318 System.arraycopy(buf, 0, tmp, out.length, len);
319 out = tmp;
320 tmp = null;
321 }
322 } catch (FileNotFoundException e) {
323 throw new ApplicationException(e);
324 } catch (IOException e) {
325 throw new ApplicationException(e);
326 } finally {
327 // always close the stream
328 if (in != null) try { in.close(); } catch (Exception e) { }
329 }
330 return out;
331 }
332
333 public String getMimeType(String fileName) throws ApplicationException {
334 String mimeType = null;
335 File file = new File(fileName);
336 try {
337 URI uri = file.toURI();
338 URL url = uri.toURL();
339 URLConnection urlConnection = url.openConnection();
340 mimeType = urlConnection.getContentType();
341 } catch (MalformedURLException e) {
342 throw new ApplicationException(e);
343 } catch (IOException e) {
344 throw new ApplicationException(e);
345 }
346 return mimeType;
347 }
348
349 /**
350 * Reads a file storing intermediate data into an array.
351 * @file file the file to be read
352 * @return byte array of the file content
353 * TODO test this method if it is really faster
354 */
355 private byte[] readBytesFast(String file) throws ApplicationException {
356 InputStream in = null;
357 byte[] buf = null;
358 int bufLen = 20000*1024;
359 try {
360 in = new BufferedInputStream(new FileInputStream(file));
361 buf = new byte[bufLen];
362 byte[] tmp = null;
363 int len = 0;
364 List data = new ArrayList(24); // keeps pieces of data
365 while((len = in.read(buf, 0, bufLen)) != -1){
366 tmp = new byte[len];
367 System.arraycopy(buf, 0, tmp, 0, len); // still need to do copy
368 data.add(tmp);
369 }
370 /* This part os optional. This method could return a List data
371 for further processing, etc. */
372 len = 0;
373 if (data.size() == 1) return (byte[]) data.get(0);
374 for (int i=0;i<data.size();i++) len += ((byte[]) data.get(i)).length;
375 buf = new byte[len]; // final output buffer
376 len = 0;
377 for (int i=0;i<data.size();i++){ // fill with data
378 tmp = (byte[]) data.get(i);
379 System.arraycopy(tmp,0,buf,len,tmp.length);
380 len += tmp.length;
381 }
382 } catch (FileNotFoundException e) {
383 throw new ApplicationException(e);
384 } catch (IOException e) {
385 throw new ApplicationException(e);
386 } finally {
387 if (in != null) try { in.close(); } catch (Exception e) {}
388 }
389 return buf;
390 }
391
392 /*
393 *
394 Insert a document (today.rss as 20050401) by a URL connection (PUT request):
395
396 URL u = "http://www.cafeaulait.org/today.rss";
397 InputStream in = u.openStream();
398 URL u = new URL("http://eliza.elharo.com:8080/exist/servlet/db/syndication/20050401");
399 HttpURLConnection conn = (HttpURLConnection) u.openConnection();
400 conn.setDoOutput(true);
401 conn.setRequestMethod("PUT");
402 conn.setHeaderField("Content-type", "application/xml");
403 OutputStream out = conn.getOutputStream();
404 for (int c = in.read(); c != -1; c = in.read()) {
405 out.write(c);
406 }
407 out.flush();
408 out.close();
409 in.close();
410 // read the response...
411
412 Delete a document (20050401) by a URL connection:
413
414 URL u = new URL("http://eliza.elharo.com:8080/exist/servlet/db/syndication/20050401");
415 HttpURLConnection conn = (HttpURLConnection) u.openConnection();
416 conn.setRequestMethod("DELETE");
417 conn.connect();
418 // read the response...
419 *
420 *
421 */
422
423
424 }