/**
* Copies a source file to a destination file, optionally preserving the source's last
* modification time. We already have an input stream to read the source file, but we know nothing
* about the destination file yet. Note that this method <em>never</em> closes the given input
* stream!
*
* @throws FileNotFoundException If either the source or the destination cannot get accessed.
* @throws InputIOException If copying the data fails because of an IOException in the source.
* @throws IOException If copying the data fails because of an IOException in the destination.
*/
private static void cp0(
final boolean preserve, final java.io.File src, final InputStream in, final java.io.File dst)
throws IOException {
try {
if (dst instanceof File) {
final File dstFile = (File) dst;
dstFile.ensureNotVirtualRoot("cannot write");
final String dstEntryName = dstFile.getEnclEntryName();
if (dstEntryName != null) {
cp0(preserve, src, in, dstFile.getEnclArchive().getArchiveController(), dstEntryName);
return;
}
}
} catch (RfsEntryFalsePositiveException dstIsNotArchive) {
}
// Treat the destination like a regular file.
final OutputStream out = new java.io.FileOutputStream(dst);
try {
Streams.cat(in, out);
} finally {
out.close();
}
if (preserve && !dst.setLastModified(src.lastModified()))
throw new IOException(dst.getPath() + " (cannot preserve last modification time)");
}
private static boolean mv0(
final java.io.File src, final java.io.File dst, final ArchiveDetector detector) {
boolean ok = true;
if (src.isDirectory()) {
final long srcLastModified = src.lastModified();
final boolean srcIsArchived = src instanceof File && ((File) src).getInnerArchive() != null;
final boolean dstIsArchived = dst instanceof File && ((File) dst).getInnerArchive() != null;
final boolean srcIsGhost = srcIsArchived && srcLastModified <= 0;
if (!srcIsGhost || !dstIsArchived || !File.isLenient()) dst.mkdir();
final String[] members = src.list();
if (!srcIsArchived && dstIsArchived) {
// Create sorted entries if writing a new archive file.
// This is courtesy only, so natural order is sufficient.
Arrays.sort(members);
}
for (int i = 0, l = members.length; i < l; i++) {
final String member = members[i];
ok &= mv0(detector.createFile(src, member), detector.createFile(dst, member), detector);
}
if (!srcIsGhost) ok &= dst.setLastModified(srcLastModified);
} else if (src.isFile()) { // !isDirectory()
try {
cp(true, src, dst);
} catch (IOException ex) {
ok = false;
}
} else {
ok = false; // don't move special files!
}
return ok && src.delete(); // only unlink if ok!
}
/** Unchecked parameters version. */
private static void cp_r0(
final boolean preserve,
final java.io.File src,
final java.io.File dst,
final ArchiveDetector srcDetector,
final ArchiveDetector dstDetector)
throws IOException {
if (src.isDirectory()) {
final long srcLastModified = src.lastModified();
final boolean srcIsArchived = src instanceof File && ((File) src).getInnerArchive() != null;
final boolean dstIsArchived = dst instanceof File && ((File) dst).getInnerArchive() != null;
final boolean srcIsGhost = srcIsArchived && srcLastModified <= 0;
if (!srcIsGhost || !dstIsArchived || !File.isLenient())
if (!dst.mkdir() && !dst.isDirectory())
throw new IOException("destination is not a directory");
final String[] members = src.list();
if (!srcIsArchived && dstIsArchived) {
// Create sorted entries if writing a new archive.
// This is a courtesy only, so natural order is sufficient.
Arrays.sort(members);
}
for (int i = 0, l = members.length; i < l; i++) {
final String member = members[i];
cp_r0(
preserve,
srcDetector.createFile(src, member),
dstDetector.createFile(dst, member),
srcDetector,
dstDetector);
}
if (preserve && !srcIsGhost)
if (!dst.setLastModified(srcLastModified))
throw new IOException("cannot set last modification time");
} else if (src.isFile() && (!dst.exists() || dst.isFile())) {
cp0(preserve, src, dst);
} else {
throw new IOException("cannot copy non-existent or special files");
}
}
/**
* Copies a source file to a destination file, optionally preserving the source's last
* modification time. We know that the source file appears to be an entry in an archive file, but
* we know nothing about the destination file yet.
*
* <p>Note that this method synchronizes on the class object in order to prevent dead locks by two
* threads copying archive entries to the other's source archive concurrently!
*
* @throws FalsePositiveException If the source or the destination is a false positive and the
* exception cannot get resolved within this method.
* @throws InputIOException If copying the data fails because of an IOException in the source.
* @throws IOException If copying the data fails because of an IOException in the destination.
*/
private static void cp0(
final boolean preserve,
final ArchiveController srcController,
final String srcEntryName,
final java.io.File dst)
throws IOException {
// Do not assume anything about the lock status of the controller:
// This method may be called from a subclass while a lock is acquired!
// assert !srcController.readLock().isLocked();
// assert !srcController.writeLock().isLocked();
try {
try {
if (dst instanceof File) {
final File dstFile = (File) dst;
dstFile.ensureNotVirtualRoot("cannot write");
final String dstEntryName = dstFile.getEnclEntryName();
if (dstEntryName != null) {
cp0(
preserve,
srcController,
srcEntryName,
dstFile.getEnclArchive().getArchiveController(),
dstEntryName);
return;
}
}
} catch (RfsEntryFalsePositiveException isNotArchive) {
// Both the source and/or the destination may be false positives,
// so we need to use the exception's additional information to
// find out which controller actually detected the false positive.
if (isNotArchive.getController() == srcController)
throw isNotArchive; // not my job - pass on!
}
final InputStream in;
final long time;
srcController.readLock().lock();
try {
in = srcController.createInputStream0(srcEntryName); // detects false positives!
time = srcController.lastModified(srcEntryName);
} finally {
srcController.readLock().unlock();
}
// Treat the destination like a regular file.
final OutputStream out;
try {
out = new java.io.FileOutputStream(dst);
} catch (IOException ex) {
try {
in.close();
} catch (IOException inFailure) {
throw new InputIOException(inFailure);
}
throw ex;
}
cp(in, out);
if (preserve && !dst.setLastModified(time))
throw new IOException(dst.getPath() + " (cannot preserve last modification time)");
} catch (ArchiveEntryFalsePositiveException ex) {
assert srcController == ex.getController();
// Reroute call to the source's enclosing archive controller.
cp0(
preserve,
srcController.getEnclController(),
srcController.enclEntryName(srcEntryName),
dst);
}
}
/**
* Returns <code>true</code> if the given file exists or can be created and at least one byte can
* be successfully written to it - the file is restored to its previous state afterwards. This is
* a much stronger test than {@link File#canWrite()}.
*
* <p>Please note that if the file is actually open for reading or other activities this method
* may not be able to reset the last modification time of the file after testing, in which case
* <code>false</code> is returned. This is known to apply to the Windows platform, but not on Unix
* platforms.
*/
public static boolean isWritableOrCreatable(final java.io.File file) {
try {
if (!file.exists()) {
final boolean created = file.createNewFile();
boolean ok = isWritableOrCreatable(file);
if (created && !file.delete()) ok = false; // be conservative!
return ok;
} else if (file.canWrite()) {
// Some operating and file system combinations make File.canWrite()
// believe that the file is writable although it's not.
// We are not that gullible, so let's test this...
final long time = file.lastModified();
if (!file.setLastModified(time + 1)) {
// This may happen on Windows and normally means that
// somebody else has opened this file
// (regardless of read or write mode).
// Be conservative: We don't allow writing to this file!
return false;
}
boolean ok;
try {
// Open the file for reading and writing, requiring any
// update to its contents to be written to the filesystem
// synchronously.
// As Dr. Simon White from Catalysoft, Cambridge, UK reported,
// "rws" does NOT work on Mac OS X with Apple's Java 1.5
// Release 1 (equivalent to Sun's Java 1.5.0_02), however
// it DOES work with Apple's Java 1.5 Release 3.
// He also confirmed that "rwd" works on Apple's
// Java 1.5 Release 1, so we use this instead.
// Thank you very much for spending the time to fix this
// issue, Dr. White!
final RandomAccessFile raf = new RandomAccessFile(file, "rwd");
try {
final boolean empty;
int octet = raf.read();
if (octet == -1) {
octet = 0; // assume first byte is 0
empty = true;
} else {
empty = false;
}
// Let's test if we can (over)write the first byte.
raf.seek(0);
raf.write((octet ^ -1) & 0xFF); // write complement
try {
// Rewrite original content and check success.
raf.seek(0);
raf.write(octet);
raf.seek(0);
final int check = raf.read();
// This should always return true unless the storage
// device is faulty.
ok = octet == check;
} finally {
if (empty) raf.setLength(0);
}
} finally {
raf.close();
}
} finally {
if (!file.setLastModified(time)) {
// This may happen on Windows and normally means that
// somebody else has opened this file meanwhile
// (regardless of read or write mode).
// Be conservative: We don't allow (further) writing to
// this file!
ok = false;
}
}
return ok;
} else { // if (file.exists() && !file.canWrite()) {
return false;
}
} catch (IOException ex) {
return false; // don't allow writing if anything goes wrong!
}
}