压缩和解压缩

现在很的app都有备份恢复功能。备份的时候都需要把文件打包，恢复的时候需要把文件解压。

压缩解压缩代码如下：

public class ZipUtils {
	/**
	 * 解压缩功能. 将zipFile文件解压到folderPath目录下.
	 * 
	 * @throws Exception
	 */
	public static int upZipFile(File zipFile, String folderPath) throws ZipException,
			IOException {
		// public static void upZipFile() throws Exception{
		ZipFile zfile = new ZipFile(zipFile);
		Enumeration zList = zfile.entries();
		ZipEntry ze = null;
		byte[] buf = new byte[1024];
		while (zList.hasMoreElements()) {
			ze = (ZipEntry) zList.nextElement();
			if (ze.isDirectory()) {
				String dirstr = folderPath + ze.getName();
				// dirstr.trim();
				dirstr = new String(dirstr.getBytes("8859_1"), "GB2312");
				File f = new File(dirstr);
				f.mkdir();
				continue;
			}
			OutputStream os = new BufferedOutputStream(new FileOutputStream(
					getRealFileName(folderPath, ze.getName())));
			InputStream is = new BufferedInputStream(zfile.getInputStream(ze));
			int readLen = 0;
			while ((readLen = is.read(buf, 0, 1024)) != -1) {
				os.write(buf, 0, readLen);
			}
			is.close();
			os.close();
		}
		zfile.close();
		return 0;
	}

	/**
	 * 给定根目录，返回一个相对路径所对应的实际文件名.
	 * 
	 * @param baseDir
	 *            指定根目录
	 * @param absFileName
	 *            相对路径名，来自于ZipEntry中的name
	 * @return java.io.File 实际的文件
	 */
	public static File getRealFileName(String baseDir, String absFileName) {
		String[] dirs = absFileName.split("/");
		File ret = new File(baseDir);
		String substr = null;
		if (dirs.length > 1) {
			for (int i = 0; i < dirs.length - 1; i++) {
				substr = dirs[i];
				try {
					// substr.trim();
					substr = new String(substr.getBytes("8859_1"), "GB2312");

				} catch (UnsupportedEncodingException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				ret = new File(ret, substr);

			}

			if (!ret.exists())
				ret.mkdirs();
			substr = dirs[dirs.length - 1];
			try {
				// substr.trim();
				substr = new String(substr.getBytes("8859_1"), "GB2312");
				
			} catch (UnsupportedEncodingException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

			ret = new File(ret, substr);
			
			return ret;
		}
		return ret;
	}

	/**
	 * 压缩文件,文件夹
	 * 
	 * @param srcFileString
	 *            要压缩的文件/文件夹名字
	 * @param zipFileString
	 *            指定压缩的目的和名字
	 * @throws Exception
	 */
	public static void ZipFolder(String srcFileString, String zipFileString)
			throws Exception {
		

		// 创建Zip包
		ZipOutputStream outZip = new ZipOutputStream(new FileOutputStream(
				zipFileString));

		// 打开要输出的文件
		File file = new File(srcFileString);

		// 压缩
		ZipFiles(file.getParent() + File.separator, file.getName(), outZip);

		// 完成,关闭
		outZip.finish();
		outZip.close();

	}// end of func

	/**
	 * 压缩文件
	 * 
	 * @param folderString
	 * @param fileString
	 * @param zipOutputSteam
	 * @throws Exception
	 */
	private static void ZipFiles(String folderString, String fileString,
			ZipOutputStream zipOutputSteam) throws Exception {
		

		if (zipOutputSteam == null)
			return;

		File file = new File(folderString + fileString);

		// 判断是不是文件
		if (file.isFile()) {

			ZipEntry zipEntry = new ZipEntry(fileString);
			FileInputStream inputStream = new FileInputStream(file);
			zipOutputSteam.putNextEntry(zipEntry);

			int len;
			byte[] buffer = new byte[4096];

			while ((len = inputStream.read(buffer)) != -1) {
				zipOutputSteam.write(buffer, 0, len);
			}

			zipOutputSteam.closeEntry();
		} else {

			// 文件夹的方式,获取文件夹下的子文件
			String fileList[] = file.list();

			// 如果没有子文件, 则添加进去即可
			if (fileList.length <= 0) {
				ZipEntry zipEntry = new ZipEntry(fileString + File.separator);
				zipOutputSteam.putNextEntry(zipEntry);
				zipOutputSteam.closeEntry();
			}

			// 如果有子文件, 遍历子文件
			for (int i = 0; i < fileList.length; i++) {
				ZipFiles(folderString, fileString + File.separator
						+ fileList[i], zipOutputSteam);
			}

		}

	}

}