• 如何在Lucene中查询自动完成/建议？（lucene查询原理）
• Algolia - 自动完成允许除查询建议之外的项目
• angularjs – ngTagsInput – 只允许选择自动完成建议？
• c# – 在Lucene中搜索TokenStream字段
• c# – 如何在Lucene.NET中搜索Field.Index.NOT_ANALYZED字段？

如何在Lucene中查询自动完成/建议？（lucene查询原理）

我正在寻找一种在Lucene中执行查询自动完成/建议的方法。我已经在Google上搜索了一些，并玩了一些，但是我看到的所有示例似乎都在Solr中设置了过滤器。我们不使用Solr，也不打算在不久的将来使用Solr，而且Solr显然无论如何都只是围绕Lucene，所以我想一定有办法做到这一点！

我已经研究过使用EdgeNGramFilter，但我意识到我必须在索引字段上运行过滤器并取出令牌，然后将其与输入的Query进行比较…我只是在努力使两者之间建立连接这两个代码有点复杂，因此非常感谢帮助！

为了清楚我在寻找什么（我意识到我并不太清楚），我正在寻找一种解决方案，其中在搜索术语时会返回建议查询的列表。在搜索字段中输入“
inter”时，它将返回建议查询的列表，例如“ internet”，“ international”等。

答案1

基于@Alexandre Victoor的回答，我在contrib程序包中（并使用其中包含的LuceneDictionary）编写了一个基于Lucene
Spellchecker的小类，它完全可以实现我想要的功能。

这允许从具有单个字段的单个源索引重新索引，并提供术语建议。结果将按照原始索引中带有该术语的匹配文档的数量进行排序，因此，较流行的术语会首先出现。似乎工作得很好：）

import java.io.IOException;import java.io.Reader;import java.util.ArrayList;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import org.apache.lucene.analysis.Analyzer;import org.apache.lucene.analysis.ISOLatin1AccentFilter;import org.apache.lucene.analysis.LowerCaseFilter;import org.apache.lucene.analysis.StopFilter;import org.apache.lucene.analysis.TokenStream;import org.apache.lucene.analysis.ngram.EdgeNGramTokenFilter;import org.apache.lucene.analysis.ngram.EdgeNGramTokenFilter.Side;import org.apache.lucene.analysis.standard.StandardFilter;import org.apache.lucene.analysis.standard.StandardTokenizer;import org.apache.lucene.document.Document;import org.apache.lucene.document.Field;import org.apache.lucene.index.CorruptIndexException;import org.apache.lucene.index.IndexReader;import org.apache.lucene.index.IndexWriter;import org.apache.lucene.index.Term;import org.apache.lucene.search.IndexSearcher;import org.apache.lucene.search.Query;import org.apache.lucene.search.ScoreDoc;import org.apache.lucene.search.Sort;import org.apache.lucene.search.TermQuery;import org.apache.lucene.search.TopDocs;import org.apache.lucene.search.spell.LuceneDictionary;import org.apache.lucene.store.Directory;import org.apache.lucene.store.FSDirectory;/** * Search term auto-completer, works for single terms (so use on the last term * of the query). * <p> * Returns more popular terms first. *  * @author Mat Mannion, M.Mannion@warwick.ac.uk */public final class Autocompleter {    private static final String GRAMMED_WORDS_FIELD = "words";    private static final String SOURCE_WORD_FIELD = "sourceWord";    private static final String COUNT_FIELD = "count";    private static final String[] ENGLISH_STOP_WORDS = {    "a", "an", "and", "are", "as", "at", "be", "but", "by",    "for", "i", "if", "in", "into", "is",    "no", "not", "of", "on", "or", "s", "such",    "t", "that", "the", "their", "then", "there", "these",    "they", "this", "to", "was", "will", "with"    };    private final Directory autoCompleteDirectory;    private IndexReader autoCompleteReader;    private IndexSearcher autoCompleteSearcher;    public Autocompleter(String autoCompleteDir) throws IOException {        this.autoCompleteDirectory = FSDirectory.getDirectory(autoCompleteDir,                null);        reOpenReader();    }    public List<String> suggestTermsFor(String term) throws IOException {        // get the top 5 terms for query        Query query = new TermQuery(new Term(GRAMMED_WORDS_FIELD, term));        Sort sort = new Sort(COUNT_FIELD, true);        TopDocs docs = autoCompleteSearcher.search(query, null, 5, sort);        List<String> suggestions = new ArrayList<String>();        for (ScoreDoc doc : docs.scoreDocs) {            suggestions.add(autoCompleteReader.document(doc.doc).get(                    SOURCE_WORD_FIELD));        }        return suggestions;    }    @SuppressWarnings("unchecked")    public void reIndex(Directory sourceDirectory, String fieldToAutocomplete)            throws CorruptIndexException, IOException {        // build a dictionary (from the spell package)        IndexReader sourceReader = IndexReader.open(sourceDirectory);        LuceneDictionary dict = new LuceneDictionary(sourceReader,                fieldToAutocomplete);        // code from        // org.apache.lucene.search.spell.SpellChecker.indexDictionary(        // Dictionary)        IndexReader.unlock(autoCompleteDirectory);        // use a custom analyzer so we can do EdgeNGramFiltering        IndexWriter writer = new IndexWriter(autoCompleteDirectory,        new Analyzer() {            public TokenStream tokenStream(String fieldName,                    Reader reader) {                TokenStream result = new StandardTokenizer(reader);                result = new StandardFilter(result);                result = new LowerCaseFilter(result);                result = new ISOLatin1AccentFilter(result);                result = new StopFilter(result,                    ENGLISH_STOP_WORDS);                result = new EdgeNGramTokenFilter(                    result, Side.FRONT,1, 20);                return result;            }        }, true);        writer.setMergeFactor(300);        writer.setMaxBufferedDocs(150);        // go through every word, storing the original word (incl. n-grams)         // and the number of times it occurs        Map<String, Integer> wordsMap = new HashMap<String, Integer>();        Iterator<String> iter = (Iterator<String>) dict.getWordsIterator();        while (iter.hasNext()) {            String word = iter.next();            int len = word.length();            if (len < 3) {                continue; // too short we bail but "too long" is fine...            }            if (wordsMap.containsKey(word)) {                throw new IllegalStateException(                        "This should never happen in Lucene 2.3.2");                // wordsMap.put(word, wordsMap.get(word) + 1);            } else {                // use the number of documents this word appears in                wordsMap.put(word, sourceReader.docFreq(new Term(                        fieldToAutocomplete, word)));            }        }        for (String word : wordsMap.keySet()) {            // ok index the word            Document doc = new Document();            doc.add(new Field(SOURCE_WORD_FIELD, word, Field.Store.YES,                    Field.Index.UN_TOKENIZED)); // orig term            doc.add(new Field(GRAMMED_WORDS_FIELD, word, Field.Store.YES,                    Field.Index.TOKENIZED)); // grammed            doc.add(new Field(COUNT_FIELD,                    Integer.toString(wordsMap.get(word)), Field.Store.NO,                    Field.Index.UN_TOKENIZED)); // count            writer.addDocument(doc);        }        sourceReader.close();        // close writer        writer.optimize();        writer.close();        // re-open our reader        reOpenReader();    }    private void reOpenReader() throws CorruptIndexException, IOException {        if (autoCompleteReader == null) {            autoCompleteReader = IndexReader.open(autoCompleteDirectory);        } else {            autoCompleteReader.reopen();        }        autoCompleteSearcher = new IndexSearcher(autoCompleteReader);    }    public static void main(String[] args) throws Exception {        Autocompleter autocomplete = new Autocompleter("/index/autocomplete");        // run this to re-index from the current index, shouldn''t need to do        // this very often        // autocomplete.reIndex(FSDirectory.getDirectory("/index/live", null),        // "content");        String term = "steve";        System.out.println(autocomplete.suggestTermsFor(term));        // prints [steve, steven, stevens, stevenson, stevenage]    }}

Algolia - 自动完成允许除查询建议之外的项目

<tags-input ng-model="tags" add-from-autocomplete-only="true">
  <auto-complete source="loadTags($query)"></auto-complete>
</tags-input>

Directory index = new RAMDirectory();
Document doc = new Document();
doc.Add(new Field("fieldName",new StandardTokenizer(new StringReader("Field Value Goes Here"))));
IndexWriter iw = new IndexWriter(index,new StandardAnalyzer());
iw.AddDocument(doc);
iw.Commit();
iw.Close();
Query q = new QueryParser("fieldName",new StandardAnalyzer()).Parse("value");
IndexSearcher searcher = new IndexSearcher(index,true);
Console.WriteLine(searcher.Search(q).Length());

doc.Add(new Field("fieldName","Field Value Goes Here",Field.Store.NO,Field.Index.ANALYZED));

Field.Index.NOT_ANALYZED

Field.Index.ANALYZED

Field.Index.NOT_ANALYZED

Field.Index.ANALYZED

QueryParser parser = 
    new QueryParser(
        Version.LUCENE_30,"content",new StandardAnalyzer(Version.LUCENE_30));