// Loosely based on the workaround posted here:
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4993360
// XXX why isn't this in Apache Commons?
public static boolean isFileWritable(File file) {
boolean isWritable = false;
if (file != null) {
boolean fileAlreadyExists = file.isFile(); // i.e. exists and is a File
if (fileAlreadyExists || !file.exists()) {
try {
// true: open for append: make sure the open
// doesn't clobber the file
new FileOutputStream(file, true).close();
isWritable = true;
if (!fileAlreadyExists) { // a new file has been "touch"ed; try to remove it
try {
if (!file.delete()) {
LOGGER.warn("Can't delete temporary test file: {}", file.getAbsolutePath());
}
} catch (SecurityException se) {
LOGGER.error("Error deleting temporary test file: " + file.getAbsolutePath(), se);
}
}
} catch (IOException | SecurityException ioe) {
}
}
}
return isWritable;
}
/**
* Detects charset/encoding for given file. Not 100% accurate for non-Unicode files.
*
* @param file File to detect charset/encoding
* @return file's charset {@link org.mozilla.universalchardet.Constants} or null if not detected
* @throws IOException
*/
public static String getFileCharset(File file) throws IOException {
byte[] buf = new byte[4096];
final UniversalDetector universalDetector;
try (BufferedInputStream bufferedInputStream =
new BufferedInputStream(new FileInputStream(file))) {
universalDetector = new UniversalDetector(null);
int numberOfBytesRead;
while ((numberOfBytesRead = bufferedInputStream.read(buf)) > 0
&& !universalDetector.isDone()) {
universalDetector.handleData(buf, 0, numberOfBytesRead);
}
}
universalDetector.dataEnd();
String encoding = universalDetector.getDetectedCharset();
if (encoding != null) {
LOGGER.debug("Detected encoding for {} is {}.", file.getAbsolutePath(), encoding);
} else {
LOGGER.debug("No encoding detected for {}.", file.getAbsolutePath());
}
universalDetector.reset();
return encoding;
}
public static boolean isFolderRelevant(
File f, PmsConfiguration configuration, Set<String> ignoreFiles) {
if (f.isDirectory() && configuration.isHideEmptyFolders()) {
File[] children = f.listFiles();
/**
* listFiles() returns null if "this abstract pathname does not denote a directory, or if an
* I/O error occurs". in this case (since we've already confirmed that it's a directory), this
* seems to mean the directory is non-readable
* http://www.ps3mediaserver.org/forum/viewtopic.php?f=6&t=15135
* http://stackoverflow.com/questions/3228147/retrieving-the-underlying-error-when-file-listfiles-return-null
*/
if (children == null) {
LOGGER.warn("Can't list files in non-readable directory: {}", f.getAbsolutePath());
} else {
for (File child : children) {
if (ignoreFiles.contains(child.getAbsolutePath())) {
continue;
}
if (child.isFile()) {
if (FormatFactory.getAssociatedFormat(child.getName()) != null
|| isFileRelevant(child, configuration)) {
return true;
}
} else {
if (isFolderRelevant(child, configuration, ignoreFiles)) {
return true;
}
}
}
}
}
return false;
}
// XXX dir.canWrite() has issues on Windows, so verify it directly:
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6203387
public static boolean isDirectoryWritable(File dir) {
boolean isWritable = false;
if (dir != null) {
// new File("").isDirectory() is false, even though getAbsolutePath() returns the right path.
// this resolves it
dir = dir.getAbsoluteFile();
if (dir.isDirectory()) {
File file =
new File(
dir,
String.format(
"pms_directory_write_test_%d_%d.tmp",
System.currentTimeMillis(), Thread.currentThread().getId()));
try {
if (file.createNewFile()) {
if (isFileWritable(file)) {
isWritable = true;
}
if (!file.delete()) {
LOGGER.warn("Can't delete temporary test file: {}", file.getAbsolutePath());
}
}
} catch (IOException | SecurityException ioe) {
}
}
}
return isWritable;
}
FileLocation(File directory, File file) {
this.directoryPath = FilenameUtils.normalize(directory.getAbsolutePath());
this.filePath = FilenameUtils.normalize(file.getAbsolutePath());
}
