Lucene BooleanQuery 嵌套使用

public long getSearchCount(String keyword, String webFlag) {
    TopScoreDocCollector f = TopScoreDocCollector.create(5000, false);
    IndexSearcher isearcher = getSearcher();
    Analyzer analyzer = null;
    QueryParser queryParser = null;
    Query query;
    try {
        if (!"website".equals(webFlag)) {
            // 在索引目錄中查詢的字段
            String[] fields = { "BOOK_NAME", "BOOK_DES", "BOOK_PEN_NAME", "BOOK_STATUS" };
            List list = new ArrayList();
            analyzer = getAnalyzer();
            queryParser = new MultiFieldQueryParser(version, fields, analyzer);
            query = queryParser.parse(keyword);
        } else {
            query = new BooleanQuery();
            BooleanQuery bquery1 = new BooleanQuery();
            TermQuery tQuery1 = new TermQuery(new Term("BOOK_NAME", keyword));
            TermQuery tQuery2 = new TermQuery(new Term("BOOK_DES", keyword));
            TermQuery tQuery3 = new TermQuery(new Term("BOOK_PEN_NAME", keyword));
            TermQuery tQuery4 = new TermQuery(new Term("BOOK_STATUS", "12"));
            TermQuery tQuery5 = new TermQuery(new Term("BOOK_ONSALE_IDE", "true"));
            bquery1.add(tQuery1, BooleanClause.Occur.SHOULD);
            bquery1.add(tQuery2, BooleanClause.Occur.SHOULD);
            bquery1.add(tQuery3, BooleanClause.Occur.SHOULD);
            //查詢條件通過BooleanQuery 嵌套使用。。
            ((BooleanQuery) query).add(bquery1, BooleanClause.Occur.MUST);**重點內容**
            ((BooleanQuery) query).add(tQuery4, BooleanClause.Occur.MUST);
            ((BooleanQuery) query).add(tQuery5, BooleanClause.Occur.MUST);
        }
        isearcher.search(query, f);
    } catch (Exception e) {
        e.printStackTrace();
    }
    TopDocs topDocs = f.topDocs(0, 5000);
    ScoreDoc[] hits = topDocs.scoreDocs;
    return hits.length;
}**重點內容**