春季启动MongoDB聚合和求和

Question

我在MongoDB实现中使用spring boot，我需要运行查询并从某些字段中获取平均值。
我有一个包含以下数据的集合

{ "_id" : 1, "domainName" : "hostgator1", "hosting" : "hostgator.com" }
{ "_id" : 2, "domainName" : "aws1", "hosting" : "aws.amazon.com"}
{ "_id" : 3, "domainName" : "aws2", "hosting" : "aws.amazon.com" }
{ "_id" : 4, "domainName" : "hostgator2", "hosting" : "hostgator.com" }
{ "_id" : 5, "domainName" : "aws2", "hosting" : "aws.amazon.com" }
{ "_id" : 6, "domainName" : "google1", "hosting" : "cloud.google.com" }
{ "_id" : 7, "domainName" : "test7.com", "hosting" : "aws.amazon.com" }
{ "_id" : 8, "domainName" : "hostgator1", "hosting" : "hostgator.com" }
{ "_id" : 9, "domainName" : "google1", "hosting" : "cloud.google.com" }
{ "_id" : 10, "domainName" : "godaddy1", "hosting" : "godaddy.com" }

这是我得到平均值的查询：

db.domain.aggregate(

    { 
    $group : {_id : {"hosting": "$hosting", "domainName" : "$domainName"}, total : { $sum : 1 }}
    },
    {
    $sort : {total : -1}
    }
);

如何在春季运行此查询？
我尝试将Aggregation类与GroupOperation一起使用，但这没有帮助