@Override
  protected void populatePut(byte[] lineBytes, ParsedLine parsed, Put put, int i)
    throws BadTsvLineException, IOException {
    KeyValue kv;
    kv = new KeyValue(lineBytes, parsed.getRowKeyOffset(), parsed.getRowKeyLength(),
      parser.getFamily(i), 0, parser.getFamily(i).length, parser.getQualifier(i), 0,
      parser.getQualifier(i).length, ts, KeyValue.Type.Put, lineBytes, parsed.getColumnOffset(i),
      parsed.getColumnLength(i));
    if (parsed.getIndividualAttributes() != null) {
      String[] attributes = parsed.getIndividualAttributes();
      for (String attr : attributes) {
        String[] split = attr.split(ImportTsv.DEFAULT_ATTRIBUTES_SEPERATOR);
        if (split == null || split.length <= 1) {
          throw new BadTsvLineException(msg(attributes));
        } else {
          if (split[0].length() <= 0 || split[1].length() <= 0) {
            throw new BadTsvLineException(msg(attributes));
          }
          put.setAttribute(split[0], Bytes.toBytes(split[1]));
        }
      }
    }
    put.add(kv);
  }
Just shows a simple example of how the attributes can be extracted and added to the puts
hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapreduce/TsvImporterCustomTestMapperForOprAttr.java