code: public static void toFile(InputStream input, File file) throws IOException {
  		OutputStream os = new FileOutputStream(file);
  		int bytesRead = 0;
  		byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
  		while ((bytesRead = input.read(buffer, 0, DEFAULT_BUFFER_SIZE)) != -1) {
  			os.write(buffer, 0, bytesRead);
  		}
  		IOUtils.closeQuietly(os);
  		IOUtils.closeQuietly(input);
  	}
docs: InputStream to File
  @param input  the <code>InputStream</code> to read from
  @param file the File to write
  @throws IOException id异常