Сложные запросы с MongoTemplate и Spring Data MongoDB

Question

Я использую простой MongoDB апи т.е. MongoClient, DB, DBCollection, AggregrationOutput и DBObejct т.д. Я следующий запрос, который работает отлично:

MongoClient mongo = new MongoClient("localhost", 27017); 
DB db = mongo.getDB("myDB"); 
DBCollection collection = db.getCollection("my_data"); 
List<DBObject> pipeline=new ArrayList<DBObject>();    
DBObject match = new BasicDBObject("$match", new BasicDBObject("date", sdf.format(new Date())).append("myName", myName)); 
DBObject unwind = new BasicDBObject("$unwind", "$myDetails"); 
DBObject match2 = new BasicDBObject("$match", new BasicDBObject("myDetails.type", "health")); 
DBObject sort = new BasicDBObject("$sort", new BasicDBObject("myDetails.datetime", -1)); 
DBObject limit = new BasicDBObject("$limit", 1); 

pipeline.add(match); 
pipeline.add(unwind); 
pipeline.add(match2); 
pipeline.add(sort); 
pipeline.add(limit); 

AggregationOutput output = collection.aggregate(pipeline); 

Теперь я хочу перейдите к SpringData mongoDb api. Может ли кто-нибудь помочь мне написать тот же запрос с MongoTemplate и MongoOperations?

Answer 1

Вот ответ, который я получил от функции агрегации MongoOperations:

ApplicationContext ctx = new AnnotationConfigApplicationContext(MongoConfig.class); 
    MongoOperations mongoOperation = (MongoOperations) ctx.getBean("mongoTemplate"); 

    AggregationOperation match = Aggregation.match(Criteria.where("country").is("India")); 
    AggregationOperation unwind = Aggregation.unwind("myDetails"); 
    AggregationOperation match2 = Aggregation.match(Criteria.where("myDetails.type").is("health")); 
    AggregationOperation sort = Aggregation.sort(Sort.Direction.ASC, "myDetails.datetime"); 
    AggregationOperation limit = Aggregation.limit(1); 

    Aggregation aggregation = Aggregation.newAggregation(match, unwind, match2, sort, limit); 
    System.out.println("Aggregation = "+aggregation); 
    AggregationResults<AggregateFactoryResult> output = mongoOperation.aggregate(aggregation, "gui_data", AggregateFactoryResult.class); 
    System.out.println("output = "+output.getMappedResults());