Zipping a folder which contains subfolders

Question

public static void main(String argv[]) {
    try {
        String date = new java.text.SimpleDateFormat("MM-dd-yyyy")
                .format(new java.util.Date());
        File inFolder = new File("Output/" + date + "_4D");
        File outFolder = new File("Output/" + date + "_4D" + ".zip");
        ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(
                new FileOutputStream(outFolder)));
        BufferedInputStream in = null;
        byte[] data = new byte[1000];
        String files[] = inFolder.list();
        for (int i = 0; i < files.length; i++) {
            in = new BufferedInputStream(new FileInputStream(
                    inFolder.getPath() + "/" + files[i]), 1000);
            out.putNextEntry(new ZipEntry(files[i]));
            int count;
            while ((count = in.read(data, 0, 1000)) != -1) {
                out.write(data, 0, count);
            }
            out.closeEntry();
        }
        out.flush();
        out.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

I'm trying to zip a folder which contains subfolders. Trying to zip the folder named 10-18-2010_4D.The above program ends with the following exception. Please advise on how to clear the issue.

java.io.FileNotFoundException: Output\10-18-2010_4D\4D (Access is denied)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(Unknown Source)
    at java.io.FileInputStream.<init>(Unknown Source)
    at ZipFile.main(ZipFile.java:17)

Answer 1

Here's the code for creating the ZIP archive. Created archive preserves original directory structure (if any).

public static void addDirToZipArchive(ZipOutputStream zos, File fileToZip, String parrentDirectoryName) throws Exception {
    if (fileToZip == null || !fileToZip.exists()) {
        return;
    }

    String zipEntryName = fileToZip.getName();
    if (parrentDirectoryName!=null && !parrentDirectoryName.isEmpty()) {
        zipEntryName = parrentDirectoryName + "/" + fileToZip.getName();
    }

    if (fileToZip.isDirectory()) {
        System.out.println("+" + zipEntryName);
        for (File file : fileToZip.listFiles()) {
            addDirToZipArchive(zos, file, zipEntryName);
        }
    } else {
        System.out.println("   " + zipEntryName);
        byte[] buffer = new byte[1024];
        FileInputStream fis = new FileInputStream(fileToZip);
        zos.putNextEntry(new ZipEntry(zipEntryName));
        int length;
        while ((length = fis.read(buffer)) > 0) {
            zos.write(buffer, 0, length);
        }
        zos.closeEntry();
        fis.close();
    }
}

Don't forget to close output streams after calling this method. Here's the example:

public static void main(String[] args) throws Exception {
    FileOutputStream fos = new FileOutputStream("C:\\Users\\vebrpav\\archive.zip");
    ZipOutputStream zos = new ZipOutputStream(fos);
    addDirToZipArchive(zos, new File("C:\\Users\\vebrpav\\Downloads\\"), null);
    zos.flush();
    fos.flush();
    zos.close();
    fos.close();
}

Answer 2

You need to check if the file is a directory because you can't pass directories to the zip method.

Take a look at this page which shows how you can recursively zip a given directory.