How can I convert byte array to ZIP file

Question

I am trying to convert an array of bytes into a ZIP file. I got bytes using the following code:

byte[] originalContentBytes= new Verification().readBytesFromAFile(new File("E://file.zip"));

private byte[] readBytesFromAFile(File file) {
    int start = 0;
    int length = 1024;
    int offset = -1;
    byte[] buffer = new byte[length];
    try {
        //convert the file content into a byte array
        FileInputStream fileInuptStream = new FileInputStream(file);
        BufferedInputStream bufferedInputStream = new BufferedInputStream(
                fileInuptStream);
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

        while ((offset = bufferedInputStream.read(buffer, start, length)) != -1) {
            byteArrayOutputStream.write(buffer, start, offset);
        }

        bufferedInputStream.close();
        byteArrayOutputStream.flush();
        buffer = byteArrayOutputStream.toByteArray();
        byteArrayOutputStream.close();
    } catch (FileNotFoundException fileNotFoundException) {
        fileNotFoundException.printStackTrace();
    } catch (IOException ioException) {
        ioException.printStackTrace();
    }

    return buffer;
}

But my problem now is with converting the byte array back into a ZIP file - how can it be done?

Note : The specified ZIP contains two files.

Answer 1

To get the contents from the bytes you can use

ZipInputStream zipStream = new ZipInputStream(new ByteArrayInputStream(bytes));
ZipEntry entry = null;
while ((entry = zipStream.getNextEntry()) != null) {

    String entryName = entry.getName();

    FileOutputStream out = new FileOutputStream(entryName);

    byte[] byteBuff = new byte[4096];
    int bytesRead = 0;
    while ((bytesRead = zipStream.read(byteBuff)) != -1)
    {
        out.write(byteBuff, 0, bytesRead);
    }

    out.close();
    zipStream.closeEntry();
}
zipStream.close(); 

Answer 2

You probably are looking for code like this:

ZipInputStream z = new ZipInputStream(new ByteArrayInputStream(buffer))

now you can get the zip file contents via getNextEntry()