convert zip byte[] to unzip byte[]

Question

I have byte[] of zip file. I have to unzip it without creating new file, and get byte[] of that unzip file. Please help me to do that

Answer 1

You can use ZipInputStream and ZipOutputStream (in the package java.util.zip) to read and write from ZIP files.

If you have the data in a byte array, you can let these read from a ByteArrayInputStream or write to a ByteArrayOutputStream pointing to your input and output byte arrays.

Answer 2

public static List<ZipEntry> extractZipEntries(byte[] content) throws IOException {
    List<ZipEntry> entries = new ArrayList<>();
   
    ZipInputStream zipStream = new ZipInputStream(new ByteArrayInputStream(content));
    ZipEntry entry = null;
    while ((entry = zipStream.getNextEntry()) != null)
    {
        System.out.println( "entry: " + entry );
        ZipOutputStream stream= new ZipOutputStream(new FileOutputStream(new File("F:\\ssd\\wer\\"+entry.getName())));
        stream.putNextEntry(entry);
    }
    zipStream.close();
   
    return entries;
}

Answer 3

In case you need to deflate your zipped data and you are too lazy to deal with the streams, you can use the following code:

public byte[] deflate(byte[] data) throws IOException, DataFormatException {
    Inflater inflater = new Inflater();
    inflater.setInput(data);
    ByteArrayOutputStream outputStream = new ByteArrayOutputStream(data.length);
    byte[] buffer = new byte[1024];
    while (!inflater.finished()) {
        int count = inflater.inflate(buffer);
        outputStream.write(buffer, 0, count);
    }
    outputStream.close();
    byte[] output = outputStream.toByteArray();
    return output;
}