ZipDecompressor.java

package com.google.gwt.dist.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.Adler32;
import java.util.zip.CheckedInputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

/**
 * Helper class that implements decompression of a stream which has been
 * previously compressed using standard zip algorithm.
 */
public class ZipDecompressor {

	private static final int BUFFER = 2048;

	/**
	 * Uncompress a stream into a directory.
	 * 
	 * @param stream
	 *            ByteArrayOutputStream to be uncompressed.
	 * @param directory
	 *            The directory into which to store the uncompressed stream.
	 * @throws IOException
	 * @throws FileNotFoundException
	 */
	public void decompressAndStoreToFile(byte[] receivedData, File directory)
			throws FileNotFoundException, IOException {
		directory.mkdir();
		BufferedOutputStream dest = null;
		ByteArrayInputStream inputStream = new ByteArrayInputStream(
				receivedData);
		CheckedInputStream checksum = new CheckedInputStream(inputStream,
				new Adler32());
		ZipInputStream zis = new ZipInputStream(new BufferedInputStream(
				checksum));
		ZipEntry entry;
		while ((entry = zis.getNextEntry()) != null) {

			// Restore directory structure.
			File destFile = new File(directory, entry.getName());
			destFile = new File(destFile.getParent());
			destFile.mkdirs();

			int count;
			byte data[] = new byte[BUFFER];
			File f = new File(directory.getAbsolutePath()
					+ Util.getFolderSeparatorInZipArchive() + entry.getName());
			f.createNewFile();
			FileOutputStream fos = new FileOutputStream(f);
			dest = new BufferedOutputStream(fos, BUFFER);
			while ((count = zis.read(data, 0, BUFFER)) != -1) {
				dest.write(data, 0, count);
			}
			dest.flush();
			dest.close();
		}
		zis.close();
	}
}