将MongoDb查询转换为Java BasicDbObject

Question

I need to convert mongodb query into java. I have "conversations" collection. Mongo db query this way and it's work.

{
    messages: { source: 1, $elemMatch: { date: { $gte: ISODate("2013-07-25 00:00:00"), $lt: ISODate("2013-08-26 00:00:00")}}}
}

And I am tring into java BasicDBObject

elemMatch = new BasicDBObject();
BasicDBObject retrievedField = new BasicDBObject();
elemMatch.put("date", new    BasicDBObject("$gte",StartDate).append("$lte",EndDate));
elemMatch.put("source", 1);
BasicDBObject up = new BasicDBObject();
up.put("$elemMatch",elemMatch);
retrievedField.put("messages", up);
DBCursor cursor  = this.dbCollection.find( retrievedField).limit(10);

but this code not working

My collection's data is

    {
    "_id" : ObjectId("51f130d6e4b0bf50e9bfc038"),
    "saleId" : 2.43564e+07,
    "saleCode" : "905155440001",
    "randomId" : 9630,
    "creatorId" : 8.21048e+06,
    "recipientId" : 4.83831e+06,
    "creatorType" : 1,
    "returnReasonId" : 11,
    "conversationClosed" : false,
    "operatorCalled" : false,
    "sellerNotified" : false,
    "buyerNotified" : false,
    "operatorCalledDate" : null,
    "creationDate" : ISODate("2013-07-25T14:06:14.967Z"),
    "lastUpdateDate" : ISODate("2013-08-15T08:46:10.115Z"),
    "messages" : [ 
        {
            "senderId" : 8.21048e+06,
            "source" : 1,
            "seenByBuyer" : true,
            "seenBySeller" : true,
            "seenByOperator" : true,
            "date" : ISODate("2013-07-25T14:06:39.968Z"),
            "messageBody" : "asdad"
        }, 
        {
            "senderId" : 8.21048e+06,
            "source" : 1,
            "seenByBuyer" : true,
            "seenBySeller" : true,
            "seenByOperator" : true,
            "date" : ISODate("2013-07-25T14:06:59.978Z"),
            "messageBody" : "asdasdawdwa"
        }, 
        {
            "senderId" : 0,
            "source" : 4,
            "seenByBuyer" : true,
            "seenBySeller" : true,
            "seenByOperator" : true,
            "date" : ISODate("2013-07-25T14:07:20.044Z"),
            "messageBody" : "ad"
        }
    ]
}

Any help?

Calendar calStartDate = Calendar.getInstance();
        Calendar calEndDate = Calendar.getInstance();
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat ("yyyy-MM-dd HH:mm:ss");
        Date StartDate = simpleDateFormat.parse(messageStartDate);
        Date EndDate = simpleDateFormat.parse(messageEndDate);

        calStartDate.setTime(StartDate);
        calEndDate.setTime(EndDate);
        Date sdate = new DateTime(calStartDate.get(Calendar.YEAR),calStartDate.get(Calendar.MONTH), calStartDate.get(Calendar.DAY_OF_MONTH),calStartDate.get(Calendar.HOUR),calStartDate.get(Calendar.MINUTE), DateTimeZone.UTC).toDate();
        Date edate = new DateTime(calEndDate.get(Calendar.YEAR), calEndDate.get(Calendar.MONTH), calEndDate.get(Calendar.DAY_OF_MONTH), calEndDate.get(Calendar.HOUR), calEndDate.get(Calendar.MINUTE), DateTimeZone.UTC).toDate();

        BasicDBObject query = new BasicDBObject(
                "messages",
                new BasicDBObject("$elemMatch",new BasicDBObject("source", 1).append("date", new BasicDBObject("$gte", sdate).append("$lt", edate)))
        );

        DBCursor cursor  = this.dbCollection.find( query).limit(10);

Answer 1

Your shell query was not correct anyway. It should be:

{
    "messages": { 
       "$elemMatch": { 
          "source": 1,
          "date": { 
              "$gte": ISODate("2013-07-25 00:00:00"),
              "$lt": ISODate("2013-07-26 00:00:00")
         }
       }
   }
}

And it helps to follow the same nesting rules so you don't get the flow incorrect:

BasicDBObject query = new BasicDBObject(
    "messages",
    new BasicDBObject(
        "$elemMatch",
        new BasicDBObject( "source", 1 )
            .append( new BasicDBObject(
               "date",
               new BasicDBObject( "$gte", StartDate )
                   .append( "$lt", EndDate )
            )
        )
    )
); 

Make sure that "dates" are of type java.util.Date returned from something like jodatime to be valid for serialization as well. And make sure that are UTC times you are constructing from.

Example:

import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;

Date StartDate = new DateTime(2013, 7, 25, 0, 0, DateTimeZone.UTC).toDate();