Lucene侧钻，带有自定义排序字段或TopCoreDocCollector

我试图用Lucene 4.6.1实现横向搜索。 以下代码可以正常工作：

DrillSideways ds = new DrillSideways(searcher, taxoReader);
FacetSearchParams fsp = new FacetSearchParams(getAllFacetCounts());

DrillDownQuery ddq = new DrillDownQuery(fsp.indexingParams, mainQuery);

List<CategoryPath> paths = new ArrayList<CategoryPath>();
...
add category path
...
if (paths.size() >0)
    ddq.add(paths.toArray(new CategoryPath[paths.size()]));

DrillSidewaysResult dsr = ds.search(null, ddq, 500, fsp); // <-- here
TopDocs topDocs = dsr.hits;
ScoreDoc[] hits = topDocs.scoreDocs;

// list search results
listSearchResults(searcher, hits, Math.min(500, topDocs.totalHits));

---

结果为空集，没有错误。怎么了？

我猜您指的是

钻边结果命中数的值，这是预期行为，如以下文档中所述：

请注意，如果调用DrillSideways.search（DrillDownQuery、Collector、FacetSearchParams），则命中数将为null

您应该从
收集器
中获得点击率

// for now it is top score collector,
// but I may want to implement custom sort
TopScoreDocCollector topDocsCollector = TopScoreDocCollector.create(500, true);
DrillSidewaysResult dsr = ds.search(ddq, topDocsCollector, fsp);