mong模板聚合匹配和投影一个字段，没有id

Question

如何运行具有匹配和投影的聚合。投影包括一个字段并排除 id。

db.collection("Collection").aggregate([

    {

        $match : {

            "someCriteriaFlag" : false

        }

    },

    {

        $project : {

            "field1" : 1,

            "_id" : 0

        }

    }

]);

在爪哇

Aggregation aggregation = Aggregation.newAggregation(

        Aggregation.match(Criteria.where("someCriteriaFlag").is(false)), 

        Aggregation.project("field1"));

List<String> fields= mongoTemplate.aggregate(aggregation, "Collection", BasicDBObject.class)

        .getMappedResults();

Answer 1

Aggregation&nbsp;aggregation&nbsp;=&nbsp;Aggregation.newAggregation( &nbsp;&nbsp;&nbsp;&nbsp;Aggregation.match(Criteria.where("someCriteriaFlag").is(false)),&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;Aggregation.project("field1").andExclude("_id")); List<String>&nbsp;fields=&nbsp;mongoTemplate.aggregate(aggregation,&nbsp;"Collection",&nbsp;BasicDBObject.class) &nbsp;&nbsp;&nbsp;&nbsp;.getMappedResults();