import org.apache.lucene.search.Hit; //导入依赖的package包/类
private String getProperty(final String propertyName) throws IOException {
  if (_dir == null) {
    return null;
  }
  try {
    return doReadOperation(new ReadOperation<String>() {
      public String execute(final IndexReader reader, final Searcher searcher, final Analyzer analyzer) throws IOException, ParseException {
        Hits hits = searcher.search(new TermQuery(new Term(FIELD_PROPERTY_KEY, propertyName)));
        Iterator<?> iterator = hits.iterator();
        if (iterator.hasNext()) {
          return ((Hit) iterator.next()).get(FIELD_PROPERTY_VALUE);
        }
        return null;
      }
    }, false);
  }
  catch (QuerySyntaxException ex) {
    throw new NoQueryPerformedException(ex);
  }
}
 

import org.apache.lucene.search.Hit; //导入依赖的package包/类
@Override
public Iterator<Conversation> iterator() {
    final Iterator<Hit> hitsIterator = hits.iterator();
    // Advance the iterator until we hit the index.
    for (int i=0; i<index; i++) {
        hitsIterator.next();
    }
    return new Iterator<Conversation>() {

        private Conversation nextElement = null;

        public boolean hasNext() {
            if (nextElement == null) {
                nextElement = getNextElement();
                if (nextElement == null) {
                    return false;
                }
            }
            return true;
        }

        public Conversation next() {
            Conversation element;
            if (nextElement != null) {
                element = nextElement;
                nextElement = null;
            }
            else {
                element = getNextElement();
                if (element == null) {
                    throw new NoSuchElementException();
                }
            }
            return element;
        }

        public void remove() {
            throw new UnsupportedOperationException();
        }

        private Conversation getNextElement() {
            if (!hitsIterator.hasNext()) {
                return null;
            }
            // If we've reached the end index, stop iterating.
            else if (index >= endIndex) {
                return null;
            }
            while (hitsIterator.hasNext()) {
                try {
                    Hit hit = hitsIterator.next();
                    // Advance the index.
                    index++;

                    long conversationID = Long.parseLong(hit.get("conversationID"));
                    return new Conversation(conversationManager, conversationID);
                }
                catch (Exception e) {
                    Log.error(e.getMessage(), e);
                }
            }
            return null;
        }
    };
}
 

import org.apache.lucene.search.Hit; //导入依赖的package包/类
@Override
public Iterator<Conversation> iterator() {
          final Iterator<Hit> hitsIterator = hits.iterator();
          // Advance the iterator until we hit the index.
          for (int i=0; i<index; i++) {
              hitsIterator.next();
          }
          return new Iterator<Conversation>() {

              private Conversation nextElement = null;

              public boolean hasNext() {
                  if (nextElement == null) {
                      nextElement = getNextElement();
                      if (nextElement == null) {
                          return false;
                      }
                  }
                  return true;
              }

              public Conversation next() {
              	Conversation element;
                  if (nextElement != null) {
                      element = nextElement;
                      nextElement = null;
                  }
                  else {
                      element = getNextElement();
                      if (element == null) {
                          throw new NoSuchElementException();
                      }
                  }
                  return element;
              }

              public void remove() {
                  throw new UnsupportedOperationException();
              }

              private Conversation getNextElement() {
                  if (!hitsIterator.hasNext()) {
                      return null;
                  }
                  // If we've reached the end index, stop iterating.
                  else if (index >= endIndex) {
                      return null;
                  }
                  while (hitsIterator.hasNext()) {
                      try {
                          Hit hit = hitsIterator.next();
                          // Advance the index.
                          index++;

                          long conversationID = Long.parseLong(hit.get("conversationID"));
                          return new Conversation(conversationManager, conversationID);
                      }
                      catch (Exception e) {
                          Log.error(e.getMessage(), e);
                      }
                  }
                  return null;
              }
          };
      }