将输入流转成字符串

/**
	 * 将输入流转成字符串
	 * 
	 * @param is
	 *            输入流
	 * @return 返回字符串
	 */
	private static String convertStreamToString(InputStream is) {
		BufferedReader reader = new BufferedReader(new InputStreamReader(is));
		StringBuilder sb = new StringBuilder();
		String line = null;
		try {
			while ((line = reader.readLine()) != null) {
				sb.append(line);
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				is.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return sb.toString();
	}