lucene3.0 中BooleanQuery 的使用

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lucene3.0中BooleanQuery 实现与或的复合搜索 .

BooleanClause用于表示布尔查询子句关系的类，包括：BooleanClause.Occur.MUST，BooleanClause.Occur.MUST_NOT，BooleanClause.Occur.SHOULD。必须包含,不能包含,可以包含三种.有以下6种组合： 

 

1．MUST和MUST：取得连个查询子句的交集。 

2．MUST和MUST_NOT：表示查询结果中不能包含MUST_NOT所对应得查询子句的检索结果。 

3．SHOULD与MUST_NOT：连用时，功能同MUST和MUST_NOT。

4．SHOULD与MUST连用时，结果为MUST子句的检索结果,但是SHOULD可影响排序。

5．SHOULD与SHOULD：表示“或”关系，最终检索结果为所有检索子句的并集。

6．MUST_NOT和MUST_NOT：无意义，检索无结果。 

 

       private static void search(String str) throws Exception {

              IndexReader reader = IndexReader.open(FSDirectory.open(new File(

                            INDEX_DIR)), true); // only searching,

              // so read-only=true

              Searcher searcher = new IndexSearcher(reader);

              Analyzer analyzer = new IKAnalyzer();

              String field = "contents";

              QueryParser parser = new QueryParser(Version.LUCENE_CURRENT, field,

                            analyzer);

              Query query = null;

              str = getKeyWord(str);

              query = parser.parse(str);

              BooleanQuery q = new BooleanQuery();

              q.add(query, BooleanClause.Occur.MUST);

              QueryParser parser2 = new QueryParser(Version.LUCENE_CURRENT, "keyword",  analyzer);

              Query q2 = parser2.parse(str);

//            q2.setBoost(10);

              q.add(q2, BooleanClause.Occur.SHOULD);

               TopScoreDocCollector collector = TopScoreDocCollector.create(10, false);

              searcher.search(q, collector);

              ScoreDoc[] hits = collector.topDocs().scoreDocs;

       }