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Download zip file when call api

FileOutputStream fos = new FileOutputStream(FILE_NAME);
ZipOutputStream zipOut = new ZipOutputStream(fos);
for (File file : files) {
FileInputStream fis = new FileInputStream(file);
ZipEntry zipEntry = new ZipEntry(file.getName());
zipOut.putNextEntry(zipEntry);
byte[] bytes = new byte[1024];
int length;
while((length = fis.read(bytes)) >= 0) {
zipOut.write(bytes, 0, length);
}
fis.close();
}
zipOut.close();
fos.close();
I have a zip file, I want to download it when I call the api.With the zip file, I don't know how to download. Hope to get help from you.

If you are using Spring/Spring Boot. You can follow this stackoverflow thread Download File in Spring

File Compression to fixed size In Java

I want to perform file compression using zip package of java.util library. The aim is to limit the compressed file to a fixed size. If the compressed file size is greater than this limit, it should be split into multiple files.
try {
fos = new FileOutputStream(p_request.getOutputFilePath() + zipFileName);
ZipOutputStream zos = new ZipOutputStream(fos);
zipEntry1 = new ZipEntry(f.getName());
fis = new FileInputStream(f.getAbsolutePath());
int count;
while ((count = fis.read(fileRAW, 0, BUFFER)) != -1) {
zipEntry1 = new ZipEntry(f.getName());
if (currentSize >= (p_request.getMaxSizePerFileInMB() * 1024 * 1024)) {
zipSplitCount++;
zos.close();
zos = new ZipOutputStream(new FileOutputStream(
p_request.getOutputFilePath() + zipFileName
+ "_" + zipSplitCount + ".zip"));
currentSize = 0;
}
zos.putNextEntry(zipEntry1);
// zos.closeEntry();
currentSize += zipEntry1.getCompressedSize();
zos.write(fileRAW, 0, count);
}
I always get compressed size as -1. Can someone advise a clean approach for this?
EDIT:
So I compressed the file into chunks of fixed size to get multi parts compressed zip of the same file as f.1.zip, f.2.zip. Now when I decompress it, is there some way to restore the original file? Currently, it says the file must be broken.
byte[] buffer = new byte[BUFFER];
ZipInputStream zis = null;
try {
zis = new ZipInputStream(new FileInputStream(f.getAbsolutePath()));
ZipEntry zipEntry = zis.getNextEntry();
while(zipEntry!=null){
String fileName = zipEntry.getName();
File newFile = new File(p_request.getOutputFilePath() + fileName);
System.out.println("file unzip : "+ newFile.getAbsoluteFile());
new File(newFile.getParent()).mkdirs();
FileOutputStream fos = new FileOutputStream(newFile);
int len;
while ((len = zis.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
fos.close();
zipEntry = zis.getNextEntry();
}
zis.closeEntry();
zis.close();

You are getting -1 because the size is not known until the Zip file has been written to disk. Compression takes place when you save the entire zip file, not when you add a new entry.
This means that you have to either:
write the zip to disk after adding each file and then measuring the zip to determine whether to keep adding to it or creating a new file
or guesstimate the size based on an average compression rate and the size of the file before compression on disk.

Zipping files with ZipOutputStream gives inconsistent results

I want to zip a text file using the java.util.ZipOutputStream class. I found two examples on the internet explaining on how to do that. This led me to the two possible implementations shown below. While both methods produce 'healthy zip files', my problem is that on every run the binary content of the file is slightly different (around the 10th byte). Does someone know if
This is intended behaviour
There is a way to always produce exactly the same result
Here is my current code:
public byte[] getZipByteArray(String fileName) throws IOException
{
byte[] result = new byte[0];
byte[] buffer = new byte[1024];
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ZipOutputStream zos = new ZipOutputStream(baos);
ZipEntry ze = new ZipEntry(fileName);
zos.putNextEntry(ze);
InputStream inputStream = ZipCompression.class.getResourceAsStream(fileName);
int len;
while ((len = inputStream.read(buffer)) > 0)
{
zos.write(buffer, 0, len);
}
zos.closeEntry();
zos.close();
result = baos.toByteArray();
return result;
}
public byte[] ZipByteArrayBuffered(String fileName) throws IOException
{
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(byteArrayOutputStream);
ZipOutputStream zipOutputStream = new ZipOutputStream(bufferedOutputStream);
File file = new File(fileName);
InputStream fileInputStream = ZipCompression.class.getResourceAsStream(file.getName());
zipOutputStream.putNextEntry(new ZipEntry(file.getName()));
IOUtils.copy(fileInputStream, zipOutputStream);
fileInputStream.close();
zipOutputStream.closeEntry();
if (zipOutputStream != null)
{
zipOutputStream.finish();
zipOutputStream.flush();
IOUtils.closeQuietly(zipOutputStream);
}
IOUtils.closeQuietly(bufferedOutputStream);
IOUtils.closeQuietly(byteArrayOutputStream);
return byteArrayOutputStream.toByteArray();
}

Byte 10 starts the file modification date and so this will always differ. See Wikipedia for the details of the zip file format.

Unable to unzip zip file created with java

I have a list of files from different locations. I create a zip file using the following the code which works without error. But when I try to unzip the file in Windows using Extract All it fails seeing unable to find any bytes, yet if I double click into the zip file itself with Windows Explorer I can see the files and individual ones can be opened and contains the correct data
ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(zipFile));
for (File next : files)
{
ZipEntry zipEntry = new ZipEntry(next.getName());
zos.putNextEntry(zipEntry);
FileInputStream in = new FileInputStream(next);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0)
{
zos.write(buf, 0, len);
}
zos.closeEntry();
in.close();
}
zos.close();

This may or may not be related but I've found using fixed byte length can lead to a loss of new line characters.
This may help:
final byte[] newLine = System.getProperty(
"line.separator").getBytes("UTF-8");
while ((line = in.readLine()) != null)
final byte[] buffer = line.getBytes("UTF-8");
out.write(buffer, 0, buffer.length);
out.write(newLine, 0, newLine.length);
}

help me translate Java code making use of bytes into jython code

how do I translate this code into jython?
ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(file + ".zip"));
byte[] buf = new byte[1024];
int len;
//Create a new Zip entry with the file's name.
ZipEntry zipEntry = new ZipEntry(file.toString());
//Create a buffered input stream out of the file
//we're trying to add into the Zip archive.
FileInputStream fin = new FileInputStream(file);
BufferedInputStream in = new BufferedInputStream(fin);
zos.putNextEntry(zipEntry);
//Read bytes from the file and write into the Zip archive.
while ((len = in.read(buf)) >= 0) {
zos.write(buf, 0, len);
}
//Close the input stream.
in.close();
//Close this entry in the Zip stream.
zos.closeEntry();
this is what I have but it Fails badly
buf=None <<<< ?
len=None <<<< ?
zipEntry=ZipEntry(file.toString())
fin=FileInputStream(file)
bin=BufferedInputStream(fin)
self._zos.putNextEntry(zipEntry)
while (len=bin.helpme_im_dying(buf)) >= 0): <<<< ?
self._zos.write(buf,0,len) <<<< ?
len = bin.read(buf) <<<< ?
bin.close()
self._zos.closeEntry()
refer to this page for information https://www.acm.org/crossroads/xrds6-3/ovp63.html

Here's an exact translation of that function (except, like your case, using bin instead of reserved keyword in).
from jarray import zeros
from java.io import BufferedInputStream, FileInputStream, FileOutputStream
from java.util.zip import ZipEntry, ZipOutputStream
def test(file):
zos = ZipOutputStream(FileOutputStream(file + ".zip"))
buf = zeros(1024, 'b')
zipEntry = ZipEntry(file)
fin = FileInputStream(file)
bin = BufferedInputStream(fin)
zos.putNextEntry(zipEntry)
len = bin.read(buf)
while len >= 0:
zos.write(buf, 0, len)
len = bin.read(buf)
bin.close()
zos.closeEntry()

It is not an answer to your question, but related. Here is a CPython version:
from zipfile import ZipFile, ZIP_DEFLATED
def test(file):
ZipFile(file+".zip", "w", ZIP_DEFLATED).write(file)

Don't use ZipFile without ensuring it is closed:
with ZipFile('spam.zip', 'w') as myzip:
myzip.write('eggs.txt')