/**
* Loop through the ZIP file, copying its entries into a new, temporary ZIP file, skipping the
* entry to be deleted. Then replace the original file with the new one.
*/
protected Integer deleteEntry() throws XMLDataStoreException {
try {
ZipInputStream inStream = this.buildZipInputStream();
File outFile = this.buildTempFile();
ZipOutputStream outStream = new ZipOutputStream(new FileOutputStream(outFile));
byte[] buffer = new byte[32768];
int inCount = 0;
int outCount = 0;
// copy all the entries except the one to be deleted
ZipEntry entry = inStream.getNextEntry();
while (entry != null) {
inCount++;
if (!this.getZipEntryName().equals(entry.getName())) {
outCount++;
outStream.putNextEntry(entry);
int byteCount;
while ((byteCount = inStream.read(buffer)) != -1) {
outStream.write(buffer, 0, byteCount);
}
outStream.closeEntry();
}
entry = inStream.getNextEntry();
}
inStream.close();
if (outCount == 0) {
// add a dummy record to an empty file so we can close it
// this is required by ZipOutputStream
outStream.putNextEntry(new ZipEntry("delete.txt"));
outStream.write(
"This file is a place-holder. The containing ZIP file should be deleted.".getBytes());
outStream.closeEntry();
}
outStream.close();
if (outCount == inCount) {
// no entries were removed - just delete the temp file
outFile.delete();
} else {
// at least one entry removed - delete the original file
this.getFile().delete();
if (outCount == 0) {
// NO entries remain - just delete the temp file too
outFile.delete();
} else {
// entries remain - replace original file with temp file
outFile.renameTo(this.getFile());
}
}
return new Integer(inCount - outCount); // should be 0 or 1
} catch (IOException ex) {
throw XMLDataStoreException.ioException(ex);
}
}
/**
* Rename the ZIP file to a temporary file, then copy its entries back into the original ZIP file,
* leaving the stream open and returning it.
*/
protected Writer buildWriteStream(boolean entryShouldExist) throws XMLDataStoreException {
try {
File inFile = this.buildTempFile();
inFile.delete(); // the file actually gets created - delete it
boolean renameSucceeded = this.getFile().renameTo(inFile);
ZipInputStream inStream = this.buildZipInputStream(inFile);
ZipOutputStream outStream = this.buildZipOutputStream();
boolean entryActuallyExists = false;
byte[] buffer = new byte[32768];
ZipEntry entry = inStream.getNextEntry();
while (entry != null) {
boolean weWantToWriteTheEntry = true;
if (this.getZipEntryName().equals(entry.getName())) {
entryActuallyExists = true;
// if we were expecting the entry, skip it;
// if we were NOT expecting the entry, allow it to be rewritten
// so the file is restored to its original condition
if (entryShouldExist) {
weWantToWriteTheEntry = false;
}
}
if (weWantToWriteTheEntry) {
outStream.putNextEntry(entry);
int byteCount;
while ((byteCount = inStream.read(buffer)) != -1) {
outStream.write(buffer, 0, byteCount);
}
outStream.closeEntry();
}
entry = inStream.getNextEntry();
}
// close and delete the temporary file
inStream.close();
inFile.delete();
// check for invalid state
if (entryShouldExist != entryActuallyExists) {
outStream.close(); // close it since we will not be returning it
// need more helpful exceptions here
if (entryActuallyExists) {
throw XMLDataStoreException.fileAlreadyExists(new File(this.getZipEntryName()));
} else {
throw XMLDataStoreException.fileNotFound(new File(this.getZipEntryName()), null);
}
}
outStream.putNextEntry(new ZipEntry(this.getZipEntryName()));
return new OutputStreamWriter(outStream);
} catch (IOException ex) {
throw XMLDataStoreException.ioException(ex);
}
}
/**
* Build and return a temporary file in the same directory and with the same extension as the
* specified file.
*/
protected File buildTempFile(File file) throws IOException {
int i = file.getName().lastIndexOf('.');
String ext = ((i == -1) ? ".zip" : file.getName().substring(i));
File tempFile = File.createTempFile("temp", ext, file.getParentFile());
return tempFile;
}