全文检索lucence的过滤出错！

hits = searcher.search(comboQuery);

是有结果的。但是加了过滤

MultiFilter multiFilter = new MultiFilter(3);

multiFilter.add(new FieldFilter("infocategor","IC0100000011"));

hits = searcher.search(comboQuery,multiFilter);

此时hits就没有结果了，请各位帮忙看一下到底什么问题？？？