Example usage for org.apache.lucene.search.suggest DocumentDictionary getEntryIterator

Introduction

In this page you can find the example usage for org.apache.lucene.search.suggest DocumentDictionary getEntryIterator.

Prototype

@Override
    public InputIterator getEntryIterator() throws IOException 

Source Link

Usage

From source file:org.lukhnos.lucenestudy.Suggester.java

License:MIT License

/**
 * Rebuild a suggestion index from the document index.
 *
 * This method iterates through the entire document index and makes sure that only unique titles
 * are indexed./*w w w  .j av a2  s. c o  m*/
 *
 * @param indexRoot The parent directory inside which both the document index and the suggestion
 *                  index lives.
 * @throws IOException
 */
public static void rebuild(String indexRoot) throws IOException {
    Path indexRootPath = Paths.get(indexRoot);
    Path suggestionPath = getSuggestionIndexPath(indexRootPath);

    // Delete the suggestion index if it exists.
    if (Files.exists(suggestionPath)) {
        Util.deletePath(suggestionPath);
    }

    // Create the suggestion index.
    Analyzer analyzer = Indexer.getAnalyzer();
    Directory suggestionDir = FSDirectory.open(getSuggestionIndexPath(indexRootPath));
    AnalyzingInfixSuggester suggester = new AnalyzingInfixSuggester(suggestionDir, analyzer);

    // Open the document index.
    Directory indexDir = FSDirectory.open(Indexer.getMainIndexPath(indexRootPath));
    IndexReader reader = DirectoryReader.open(indexDir);

    // Get a document iterator.
    DocumentDictionary docDict = new DocumentDictionary(reader, Indexer.TITLE_FIELD_NAME, null);
    InputIterator iterator = docDict.getEntryIterator();
    Set<BytesRef> titleSet = new HashSet<>();
    BytesRef next;
    while ((next = iterator.next()) != null) {
        if (titleSet.contains(next)) {
            continue;
        }

        titleSet.add(next);
        suggester.add(next, null, 0, null);
    }

    reader.close();

    suggester.commit();
    suggester.close();
}

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