public static byte[] getFilterName(byte[] filterStringAsByteArray) {
    int filterNameStartIndex = 0;
    int filterNameEndIndex = 0;

    for (int i = filterNameStartIndex; i < filterStringAsByteArray.length; i++) {
      if (
        filterStringAsByteArray[i] == ParseConstants.LPAREN
          || filterStringAsByteArray[i] == ParseConstants.WHITESPACE
      ) {
        filterNameEndIndex = i;
        break;
      }
    }

    if (filterNameEndIndex == 0) {
      throw new IllegalArgumentException("Incorrect Filter Name");
    }

    byte[] filterName = new byte[filterNameEndIndex - filterNameStartIndex];
    Bytes.putBytes(filterName, 0, filterStringAsByteArray, 0,
      filterNameEndIndex - filterNameStartIndex);
    return filterName;
  }
Returns the filter name given a simple filter expression
<p>
@param filterStringAsByteArray a simple filter expression
@return name of filter in the simple filter expression
hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ParseFilter.java