Some times the easy stuff requires custom code. Searching the web I found a few examples. This one was the most promising, but it has some typos: Example Dir Zip.

So I rolled my own. Note that I use commons logging. If you don’t use logging, just remove the log statements.

Also note bad source or destination errors are silently swallowed. I will probably change this.

Also, it doesn’t do any sort of locking. Probably at a minimum the destination file should be locked.

/**
	 * Zips the directory and all contents from dir into a file named
	 * filename
	 *
	 * @param dirPath path of directory to zip; must exist
	 * @param filename filename to store contents
	 */
	public static void zipDir(String dirPath, String filename) {
		File dir = new File(dirPath);
		if (!dir.isDirectory()) {
			log.error(dirPath + " is not a directory");
			return;
		}

		ZipOutputStream out = null;

		try {
			log.trace("Creating : " + filename);
			out = new ZipOutputStream(new FileOutputStream(filename));
			addDir(dir, out);

		} catch (IOException e) {
			log.error(e);

		} finally {
			if (out != null) {
				try {
					out.close();
				} catch (IOException e) {
					log.error("failed to close output file: " + filename, e);
				}
			}
		}

	}

	private static void addDir(File dir, ZipOutputStream out)
			throws IOException {
		byte[] tmpBuf = new byte[1024];

		// add each file
		// if file is a directory, move into it and add all contents recursively
		// until done
		for (File file : dir.listFiles()) {
			if (file.isDirectory()) {
				addDir(file, out);
				continue;
			}

			FileInputStream in = new FileInputStream(file.getAbsolutePath());
			log.trace("Adding: " + file.getAbsolutePath());

			out.putNextEntry(new ZipEntry(file.getAbsolutePath()));

			// Transfer from the file to the ZIP file
			int len;
			while ((len = in.read(tmpBuf)) > 0) {
				out.write(tmpBuf, 0, len);
			}

			// Complete the entry
			out.closeEntry();
			in.close();
		}
	}