Create a zip file with several entries

createZipAsByteArray.java

private byte[] createZipAsByteArray(Path path, Map<String, File> files) throws IOException {
    String pathToZip = path.toString()+File.separator+"content.zip";
    FileOutputStream fileOutputStream = new FileOutputStream(pathToZip);
    ZipOutputStream zipOutputStream = new ZipOutputStream(fileOutputStream);
    byte[] buffer = new byte[1024];
    int len;
    for(Map.Entry<String, File> file: files.entrySet()) {
        FileInputStream fileInputStream2 = new FileInputStream(file.getValue());
        ZipEntry zipEntry = new ZipEntry(file.getKey());
        zipOutputStream.putNextEntry(zipEntry);
        while ((len = fileInputStream2.read(buffer)) > 0) {
            zipOutputStream.write(buffer, 0, len);
        }
        fileInputStream2.close();
        zipOutputStream.closeEntry();
    }
    zipOutputStream.close();
    return Files.readAllBytes(new File(pathToZip).toPath());
}