Exact Phrase search using Lucene?
I am using SpanTerm Query for searching exact phrase in lucene. But it doesnt seem to work. Here is my code.
Indexing
IndexWriter writer = new IndexWriter(dir, new StandardAnalyzer(Version.LUCENE_30), false,IndexWriter.MaxFieldLength.UNLIMITED);
doc.add(new Field("contents", sb.toString(), Field.Store.YES, Field.Index.ANALYZED,Field.TermVector.WITH_POSITIONS_OFFSETS));
doc.add(new Field("imageid", imageDocument.getImageId(), Field.Store.YES, Field.Index.NOT_ANALYZED));
doc.add(new Field("title", imageDocument.getTitle(), Field.Store.YES, Field.Index.ANALYZED));
doc.add(new Field("country", imageDocument.getCountry(), Field.Store.YES, Field.Index.NOT_ANALYZED));
write.addDocument(doc);
Searching
String sentence = searchParameters.get("searchExactWord");
String[] words = sentence.split(" ");
String queryNoWord = "";
int i = 0;
SpanTermQuery [] clause = new SpanTermQuery[words.length];
for (String word : words)
{
clause[i] = new SpanTermQuery(new Term("contents",word));
i++;
}
SpanNearQuery query = new SpanNearQuery(clause, 0, true);
booleanQuery.add(query, BooleanClause.Occur.MUST);
Please guide me if I am doing it wrong???
Prateek
Solution 1:
Try a PhraseQuery
instead:
PhraseQuery query = new PhraseQuery();
String[] words = sentence.split(" ");
for (String word : words) {
query.add(new Term("contents", word));
}
booleanQuery.add(query, BooleanClause.Occur.MUST);
Edit: I think you have a different problem. What other parts are there to your booleanQuery
? Here's a full working example of searching for a phrase:
public class LucenePhraseQuery {
public static void main(String[] args) throws Exception {
// setup Lucene to use an in-memory index
Directory directory = new RAMDirectory();
Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_30);
MaxFieldLength mlf = MaxFieldLength.UNLIMITED;
IndexWriter writer = new IndexWriter(directory, analyzer, true, mlf);
// index a few documents
writer.addDocument(createDocument("1", "foo bar baz"));
writer.addDocument(createDocument("2", "red green blue"));
writer.addDocument(createDocument("3", "test foo bar test"));
writer.close();
// search for documents that have "foo bar" in them
String sentence = "foo bar";
IndexSearcher searcher = new IndexSearcher(directory);
PhraseQuery query = new PhraseQuery();
String[] words = sentence.split(" ");
for (String word : words) {
query.add(new Term("contents", word));
}
// display search results
TopDocs topDocs = searcher.search(query, 10);
for (ScoreDoc scoreDoc : topDocs.scoreDocs) {
Document doc = searcher.doc(scoreDoc.doc);
System.out.println(doc);
}
}
private static Document createDocument(String id, String content) {
Document doc = new Document();
doc.add(new Field("id", id, Store.YES, Index.NOT_ANALYZED));
doc.add(new Field("contents", content, Store.YES, Index.ANALYZED,
Field.TermVector.WITH_POSITIONS_OFFSETS));
return doc;
}
}
Solution 2:
Use Lucene Query Builder, and give double quotes around the search string. It works for exact phrase search.
Reference: http://www.lucenetutorial.com/lucene-query-builder.html
Solution 3:
For version 4.6.0 Indexing:
IndexWriterConfig config=new IndexWriterConfig(Version.LUCENE_46,analyzer);
try {
IndexWriter iwriter=new IndexWriter(mDir,config);
iwriter.deleteAll();
iwriter.commit();
Document doc = new Document();
doc.add(new Field(myfieldname,text,TextField.TYPE_STORED));
iwriter.addDocument(doc);
iwriter.close();
}
Searching for exact phrase (given in variable keyword):
DirectoryReader ireader=DirectoryReader.open(mDir);
IndexSearcher isearcher=new IndexSearcher(ireader);
QueryParser parser = new QueryParser(Version.LUCENE_46,myfieldname,analyzer);
parser.setDefaultOperator(QueryParser.Operator.AND);
parser.setPhraseSlop(0);
Query query=parser.createPhraseQuery(myfieldname,keyword);
ScoreDoc[] hits=isearcher.search(query, null, 1000).scoreDocs;
nret=hits.length;
ireader.close();
Note for the use of "setPhraseSlop(0) and createPhraseQuery()