solr facet 分组查询

xywuyiba7

　　最近再用apache的solr，觉得很好用

现在用它实现一个分组查询



public static Map<String, Integer> queryByGroup(String qStr,String groupField,String sortField,boolean asc,Integer pageSize,Integer pageNum){
Map<String, Integer> rmap = new LinkedHashMap<String, Integer>();
try {
SolrServer server = getSolrServer();//getSolrServer() 方法就是返回一个CommonsHttpSolrServer
SolrQuery query = new SolrQuery();
if(qStr!=null&&qStr.length()>0)
query.setQuery(qStr);
else
query.setQuery("*:*");//如果没有查询语句，必须这么写，否则会报异常
query.setIncludeScore(false);//是否按每组数量高低排序
query.setFacet(true);//是否分组查询
query.setRows(0);//设置返回结果条数，如果你时分组查询，你就设置为0
query.addFacetField(groupField);//增加分组字段
query.setFacetSort(true);//分组是否排序
query.setFacetLimit(pageSize);//限制每次返回结果数
query.setSortField(sortField,asc ? SolrQuery.ORDER.asc :SolrQuery.ORDER.desc );//分组排序字段
query.set(FacetParams.FACET_OFFSET,(pageNum-1)*pageSize);//当前结果起始位置
QueryResponse rsp = server.query( query );   
List<Count> countList = rsp.getFacetField(groupField).getValues();
List<Count> returnList = new ArrayList<Count>();
if(pageNum*pageSize<countList.size())
returnList = countList.subList((pageNum-1)*pageSize,pageNum*pageSize);
else
returnList = countList.subList((pageNum-1)*pageSize,countList.size()-1);
for (Count count : returnList) {
if(count.getCount()>0)
rmap.put(count.getName(), (int) count.getCount());
}
} catch (Exception e) {
e.printStackTrace();
}
return rmap;
}