code: public static String getString(final InputStream is, String encoding) {
  
  		if (is == null) {
  			return null;
  		}
  
  		if (StringUtils.isNullOrEmptyTrimmed(encoding)) {
  			encoding = UTF_8;
  		}
  
  		final char[] buffer = new char[BUFFER_SIZE];
  		final StringBuilder out = new StringBuilder();
  		try {
  			try (Reader in = new InputStreamReader(is, encoding)) {
  				for (; ; ) {
  					int rsz = in.read(buffer, 0, buffer.length);
  					if (rsz < 0) {
  						break;
  					}
  					out.append(buffer, 0, rsz);
  				}
  			}
  		}
  		catch (IOException ioe) {
  			throw new RuntimeException(ioe);
  		}
  		return out.toString();
  	}
docs: Load input stream into string
  
  @param is       stream
  @param encoding to use when reading input stream
  @return String representation of given input