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zip,move and size of file which is in a server path using java

I have a file in the server, I want to create three java APIs, which will do the below three operations in dependently.
Get the file size
Move a file with different file name to a different server location
Zip the file
In my existing code we are executing Linux commands to perform those operations, unfortunately, Linux commands are not getting executed, this is due to some server/set up issue, so I am forced to use Java commands.(We use JDK 1.6)
I am not a Java developer. I have gone through some of the previously answered questions, but they are not explaining about file in server path. Any help is much appreciated.

To get the file size in bytes:
File file = new File("filename.txt");
long fileSize = file.length();
To move a file you must first copy it and then delete the original:
InputStream inStream = null;
OutputStream outStream = null;
try {
File fromFile = new File("startfolder\\filename.txt");
File toFile = new File("endfolder\\filename.txt");
inStream = new FileInputStream(fromFile);
outStream = new FileOutputStream(toFile);
byte[] buffer = new byte[1024];
int length;
while ((length = inStream.read(buffer)) > 0){
outStream.write(buffer, 0, length);
}
inStream.close();
outStream.close();
fromFile.delete();
} catch(IOException e) {
e.printStackTrace();
}
To zip a file:
byte[] buffer = new byte[1024];
try {
FileInputStream fileToZip = new FileInputStream("filename.txt");
FileOutputStream fileOutputStream = new FileOutputStream("filename.zip");
ZipOutputStream zipOutputStream = new ZipOutputStream(fileOutputStream);
ZipEntry zipEntry= new ZipEntry("filename.txt");
zipOutputStream.putNextEntry(zipEntry);
int len;
while ((len = fileToZip.read(buffer)) > 0) {
zipOutputStream.write(buffer, 0, len);
}
fileToZip.close();
zipOutputStream.closeEntry();
zipOutputStream.close();
} catch(IOException e) {
e.printStackTrace();
}

How to set deflater to HUFFMAN_ONLY in GZIPOutputstream

Hi i am just wondering is it possible to set the deflater used in gzip output stream to use HUFFMAN_ONLY, i have it working with my own deflate method.
public static byte[] deflate(byte[] data) throws IOException {
Deflater deflater = new Deflater();
deflater.setInput(data);
ByteArrayOutputStream outputStream = new ByteArrayOutputStream(data.length);
deflater.finish();
deflater.setLevel(Deflater.BEST_COMPRESSION); //*****THESE 2 LINES HERE
deflater.setStrategy(Deflater.HUFFMAN_ONLY); // *******
byte[] buffer = new byte[1024];
while (!deflater.finished()) {
int count = deflater.deflate(buffer); // returns the generated code... index
outputStream.write(buffer, 0, count);
}
outputStream.close();
byte[] output = outputStream.toByteArray();
return output;
}
so basically i want to know how to set the deflater used in my gzip method to the same as the deflater above when i use the lines:
deflater.setLevel(Deflater.BEST_COMPRESSION);
deflater.setStrategy(Deflater.HUFFMAN_ONLY);
this is my gzip method:
//GZIP Compression method
public static byte[] compress(String data) throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream(data.length());
GZIPOutputStream gzip = new GZIPOutputStream(bos);
gzip.write(data.getBytes());
gzip.close();
byte[] compressed = bos.toByteArray();
bos.close();
return compressed;
}

No, but you can just use Deflater with nowrap set to true, and write your own gzip header and trailer.

Unable to zip and download files in unix server

I have hosted my java web application in a unix server the files are generated in a context path,zipped and downloaded to the client. My code is working once I have hosted the Application in a Windows server but not in Centos .. What could be the issue?
My zip Method:
private byte[] zipFiles(File directory, String[] files) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ZipOutputStream zos = new ZipOutputStream(baos);
byte bytes[] = new byte[2048];
for (String fileName : files) {
FileInputStream fis = new FileInputStream(directory.getPath()
+ crbServlet.FILE_SEPARATOR + fileName);
BufferedInputStream bis = new BufferedInputStream(fis);
zos.putNextEntry(new ZipEntry(fileName));
int bytesRead;
while ((bytesRead = bis.read(bytes)) != -1) {
zos.write(bytes, 0, bytesRead);
}
zos.closeEntry();
bis.close();
fis.close();
}
zos.flush();
baos.flush();
zos.close();
baos.close();
return baos.toByteArray();
}
My servlet Extract:
String[] files = f.list();
if (files != null && files.length > 0) {
byte[] zip = zipFiles(f, files);
ServletOutputStream sos = response.getOutputStream();
response.setContentType("application/zip");
response.setHeader("Content-Disposition", "attachment; filename=\"datafiles" + dt.getCurrentDate() + ".zip\"");
sos.write(zip);
sos.flush();
}
What I am getting downloaded on the client side is a do file that has junk character. What is the issue here?

Java GZIPOutputStream: Corrupted gzip with this method

does someone have an idea why this code to create a gzipped string is not working? CLI gzip on a Mac can't open the resulting file: "Not in gz format".
Please note: I need the string, not the file. Creating the gzipped file directly works, so does writing the JSON without zipping it.
The file writing in this example is just for testing purposes.
public someMethod {
String gzippedString = this.gzippedString(finalJSONObject.toJSONString());
OutputStream outputStream = new FileOutputStream(new File(this.jsonOutputPath + "/myfile.gz"));
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream));
writer.append(gzippedString);
writer.close();
}
private String gzippedString(String inputString) throws IOException {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
GZIPOutputStream gzipOutputStream = new GZIPOutputStream(outputStream);
gzipOutputStream.write(inputString.getBytes());
gzipOutputStream.close();
outputStream.close();
String gzippedString = outputStream.toString();
return gzippedString;
}
EDIT:
chrylis showed me the way:
public void someMethod() {
byte[] byteArray = this.gzippedByteArray(finalJSONObject.toJSONString());
FileOutputStream out = new FileOutputStream(this.jsonOutputPath + "/myfile.gz");
out.write(byteArray);
out.close();
}
private byte[] gzippedByteArray(String inputString) throws IOException {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
GZIPOutputStream gzipOutputStream = new GZIPOutputStream(outputStream);
gzipOutputStream.write(inputString.getBytes());
gzipOutputStream.close();
outputStream.close();
byte[] gzippedByteArray = outputStream.toByteArray();
return gzippedByteArray;
}
This results in a working gzipped JSON.
Thanks a lot!

You're round-tripping binary data through a String, which has a character encoding and other such mangling. Use the byte[] directly instead.

EOFException: Unexpected end of ZLIB input stream

I am facing this issue while unzipping a file and writing it in to another file. Here is the code. Can any one please let me know what changes are required.
I get this exception on the line with while ((len = zis.read(buffer)) > 0)
private FileItem readZippedFileRequest(HttpServletRequest request,Part part, String fileName) {
FileItem fileItem = null;
byte[] buffer = new byte[1024];
InputStream inputStream = part.getInputStream();
ZipInputStream zis = new ZipInputStream(inputStream);
ZipEntry entry;
while ((entry = zis.getNextEntry()) != null) {
ByteArrayOutputStream fos = new ByteArrayOutputStream();
int len;
while ((len = zis.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
InputStream myByteArray = new ByteArrayInputStream(fos.toByteArray());
fileItem = createCSVFile(myByteArray, fileName,ImportExportConstant.FILE_TYPE_EXCEL);
}
return fileItem;
}

There's nothing wrong with your code. There is something wrong with the file, as the message says. Are you sure it is zipped, and not GZipped for example? It would be more usual for a part to be GZipped. Try a GZIPInputStream.
NB there's no need for the ByteArrayInputStream. It's a complete waste of time and space. Just pass the zip/gzip input stream directly to your createCSVFile() method.

I have this error too and I searched a little bit... I've read that there must be zis.closeEntry(); before len = zis.read(buffer) but I tried it and then the error appears at zis.closeEntry();
I asked google and here is the answer:
!Answer!
I tried and wrote a little bit, then I switched the throws IOException in a try/catch-block and now there is all right.
The Exception is a well known bug. You have to put all in a try/catch-block and do nothing in the catch.
private FileItem readZippedFileRequest(HttpServletRequest request,Part part, String fileName) {
FileItem fileItem = null;
byte[] buffer = new byte[1024];
try{
InputStream inputStream = part.getInputStream();
ZipInputStream zis = new ZipInputStream(inputStream);
ZipEntry entry;
while ((entry = zis.getNextEntry()) != null) {
ByteArrayOutputStream fos = new ByteArrayOutputStream();
int len;
while ((len = zis.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
InputStream myByteArray = new ByteArrayInputStream(fos.toByteArray());
fileItem = createCSVFile(myByteArray, fileName,ImportExportConstant.FILE_TYPE_EXCEL);
}
}catch(IOException ex){
//Do nothing here
}
return fileItem;
}