Review

13

org/apache/lucene/search/SortField.java

detectFieldType(IndexReader, String)

class SortField {
  /**
   * Attempts to detect the given field type for an IndexReader.
   * @deprecated
   */
  static int detectFieldType(IndexReader reader, String fieldKey) throws IOException {
    String field = StringHelper.intern(fieldKey);
    TermEnum enumerator = reader.terms(new Term(field));
    try {
      Term term = enumerator.term();
      if (term == null) {
        throw new RuntimeException("no terms in field " + field + " - cannot determine sort type");
      }
      int ret = 0;
      if (term.field() == field) {
        String termtext = term.text().trim();

        try {
          Integer.parseInt (termtext);
          ret = SortField.INT;
        } catch (NumberFormatException nfe1) {
          try {
            Long.parseLong(termtext);
            ret = SortField.LONG;
          } catch (NumberFormatException nfe2) {
            try {
              Float.parseFloat (termtext);
              ret = SortField.FLOAT;
            } catch (NumberFormatException nfe3) {
              ret = SortField.STRING;
            }
          }
        }         
      } else {
        throw new RuntimeException("field \"" + field + "\" does not appear to be indexed");
      }
      return ret;
    } finally {
      enumerator.close();
    }
  }

}