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Unable to compress a CSV file Java

I'm trying to convert an existing CSV file to a gzip file.
I verified the CSV looks good. Once I run this code, I get a "failed to expand" error and tried an online decompression tool that also failed, so it seems the output zip is corrupt.
public void compressGzip(String input, String dest) throws IOException {
Path pathSource = Paths.get(input);
Path destSource = Paths.get(dest);
try (GZIPOutputStream gos = new GZIPOutputStream(
new FileOutputStream(destSource.toFile()));
FileInputStream fis = new FileInputStream(pathSource.toFile())) {
byte[] buffer = new byte[1024];
int len;
while ((len = fis.read(buffer)) > 0) {
gos.write(buffer, 0, len);
}
}
}
Anything I could be missing here?

android copy mp3 file success but duration not change

i try to copy mp3 file in external storage and limit duration of new file. it work but when it started, although i run to limit time, it still display end time like old file.
private void copy(File in, File out) throws IOException {
FileInputStream is = null;
FileOutputStream os = null;
try {
is = new FileInputStream(in);
os = new FileOutputStream(out);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer)) > 0 && out.length()<175642) {
os.write(buffer, 0, length);
}
} finally {
assert is != null;
is.close();
assert os != null;
os.close();
}
}
how can i fix it. i really expect your help. have a nice day,everyone!

You simply cut of the rest of the file. This leads to a kind of corrupted file because the data in the header-block (e.g. the length) is no longer correct.
For some information about the mp3 file format:
https://en.wikipedia.org/wiki/MP3
I highly recommend to adjust the header information after shortening the file.

ZIP file created using Java showing empty when open with Windows Explorer

The below code is used to zip normal text file. When I extract using WinRaR its showing the content properly, but when I open with Windows Explorer its empty, no file listed. I am using Windows 7 Enterprise (64 bit) operating system. Any idea why its not listing in Windows explorer? Thanks in advance.
File file = new File("F:\\sample.txt");
byte[] buf = new byte[1024];
String outFilename = "F:\\zipped_sample.zip";
try {
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(outFilename));
FileInputStream in = new FileInputStream(file);
out.putNextEntry(new ZipEntry(file.toString()));
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
out.flush();
}
out.closeEntry();
out.close();
in.close();
} catch (Exception e) {
// log exception here
}

ZipEntry constructor takes name but you are providing it a path by doing file.toString(); Try:
New ZipEntry(file.getName());
This will pass the file name.

i had the same problem zip file were not extracted and was shown as empty the problem was in the folder names in zip file. If folder name consist of > or < symbols i saw the failure . SO in the code new ZipEntry(file.toString()) i try to clean up any folder names with those particular symbols

making zip process more optimized one

I have developed a method to zip a file that will take file path and filename as a parameter and will zip a file as shown below could you please advise how can I modify this method to be more efficient and more fast as I am a big fan of optimization..
public File generateZipForAFile(String folderPath, String reportFileName)
throws FileNotFoundException, IOException {
File inputFile = new File(folderPath + reportFileName);
FileInputStream in = new FileInputStream(inputFile);
File outputZipFile = new File(folderPath, reportFileName + ".zip");
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(outputZipFile));
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry(reportFileName ));
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
out.closeEntry();
out.close();
in.close();
return outputZipFile;
}

There is not much you can do in your code. Furthermore, most of the time is spent while actually doing the zip.
So even if you reduce the time spent in your part to 0 the overall gain will be very small.

Whats wrong with this zip method?

I have a method which zips up 5 files. It produces a zip file without error, but I cannot open it to examine the contents. I tried emailing it and gmail said it cannot send corrupt files. Trying to open with WinRAR in Windows results in an error stating:
The archive is either in unknown format or damaged
This is the method:
private void zipTestFiles() throws FileNotFoundException, IOException
{
File[] filenames = fileDir.listFiles(fileNameFilter(Constants.PAGE_MON_FILENAME_FILTER));
byte[] buf = new byte[1024];
String outFilename = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separatorChar + Constants.PAGEMONITOR_ZIP;
DeflaterOutputStream out = new DeflaterOutputStream(new BufferedOutputStream(new FileOutputStream(outFilename)));
for (int i=0; i<filenames.length; i++)
{
FileInputStream in = new FileInputStream(filenames[i]);
int len;
while ((len = in.read(buf)) > 0)
{
out.write(buf, 0, len);
}
in.close();
}
out.close();
}

You should use ZipOutputStream instead of DeflaterOutputStream. And do not forget to create entries. Read javadoc of ZipOutputStream before writing the implementation.

Try with ZipOutputStream which already exists in Java. DeflaterOutputStream only uses DEFLATE method to compress but doesn't put ZIP headers automatically.