private static void generateKeyStruct(String compositeKeyTypes, StringBuilder sb) {
    sb.append("struct<");

    // composite key types is a comma separated list of different parts of the
    // composite keys in
    // order in which they appear in the key
    String[] keyTypes = compositeKeyTypes.split(",");

    for (int i = 0; i < keyTypes.length; i++) {
      sb.append("col" + i).append(":").append(keyTypes[i]).append(StringUtils.COMMA_STR);
    }

    // trim the trailing ","
    trim(sb);
    sb.append(">");
  }
Auto-generates the key struct for composite keys

@param compositeKeyTypes comma separated list of composite key types in order
@param sb StringBuilder object to construct the struct
hbase-handler/src/java/org/apache/hadoop/hive/hbase/HBaseSerDeHelper.java