mongoTemplate按时间分组查询没有结果

[a1exlee]

如题，文档结构如下：

需求：按照日期分组，求出每天的数据总数。

使用robomongo客户端查询两种方式均能查出结果。如下：

db.runCommand(
{ group : 
	{ 
	ns: "Incident" ,
	cond : { "$and" : [ { "source" : "外点机房动环"}]} ,
	$reduce : function Reduce(doc, out) {
				if(doc._id){     
					out.count +=1;    
				} 
				} , 
	initial : { "count" : 0} ,
	$keyf : function(doc){  
				var date = new Date(doc.lastOccurTime); 
				var dateKey = '' + date.getFullYear()+ '-' + (date.getMonth()+1) + '-' + date.getDate() ;
				return {'day':dateKey};  
				}
				}
}
)

结果：

db.getCollection('Incident').group({
    keyf:function(doc){ 
    var date = new Date(doc.lastOccurTime); 
    var dateKey = '' + date.getFullYear()+ '-' + (date.getMonth()+1) + '-' + date.getDate() ;  
        return {'day':dateKey}},
        cond:{ "$and" : [ { "source" : "外点机房动环"}]},
        initial:{"count":0},
        reduce:function Reduce(doc, out) {  
        if(doc._id){    
            out.count +=1; 
            }}
    })

结果：

现在按照网上的方式，使用spring的mongoTemplate查询却是空的，麻烦各位大牛帮忙看下java代码应该怎么写：

criteria.andOperator(Criteria.where("source").is("外点机房动环"));
			Query query = Query.query(criteria);
			BasicDBObject initial = new BasicDBObject();
			initial.put("count", 0);
			String reduce = "function Reduce(doc, out) { " 
						+ "   if(doc._id){ " 
						+ "     out.count +=1; " 
						+ "   } " 
						+ " }";
			String keyf = "function(doc){ " 
						+ "   var date = new Date(doc.lastOccurTime); "
						+ "   var dateKey = '' + date.getFullYear()+ '-' + (date.getMonth()+1) + '-' + date.getDate() ; "
						+ "   return {'day':dateKey};  " 
						+ " }";
			DBCollection collection = mongoTemplate.getCollection("Incident");
			GroupCommand Gc = new GroupCommand(collection, keyf, query.getQueryObject(), initial, reduce, null);
			logger.debug("GC:" + Gc.toDBObject().toString());
			DBObject object = mongoTemplate.getCollection("Incident").group(Gc);
			logger.debug("result:" + object.toString());