MONGO in Java

1. Query.fields (). Include ("IDFA"). Include ("IMEI"). Include ("id"). include ("OS"). These fields are included in the return data

2.

①
list<criteria> criterias = new arraylist<> ();

Criterias.add (Criteria.where ("Time"). GT ("2017-09-20 10:02:26"));

Criterias.add (Criteria.where ("time"). Lt ("2017-09-27 10:02:26"));

Criterias.add (Criteria.where ("IMEI"). Is ("9686854123"));

Query.addcriteria (New Criteria () Andoperator (Criterias.toarray (new criteria[0]));

Ii
ToArray explanation

Public <T> t[] ToArray (t[] a) {

if (a.length < size)

a = (t[]) Java.lang.reflect.Array.

Newinstance (A.getclass (). Getcomponenttype (), size);

system.arraycopy (elementdata, 0, a, 0, size);

if (a.length > Size)

A[size] = null;

return A;

}

The following query statement is obtained by ①

{"Channel":"Jinritoutiao","$and": [ {"IMEI":"96868541236"}, {" Time": {"$lt":"2017-09-27 10:02:26"}}, {" Time": {"$GT":"2017-09-20 10:02:26"}}]
}

3.

Query.addcriteria (Criteria.where ("Key"). Is ("Value"));

from the source below can be seen above the key cannot be a duplicate value


PublicQuery Addcriteria (criteriadefinition criteriadefinition) {criteriadefinition existing= (criteriadefinition) This. Criteria.Get(Criteriadefinition.getkey ()); String Key=Criteriadefinition.getkey (); if(Existing = =NULL) {             This. Criteria.put (key, criteriadefinition); return  This; } Else {            Throw NewInvalidmongodbapiusageexception ("Due to limitations of the com.mongodb.BasicDBObject, you can ' t add a second '"+ key +"' criteria."+"Query already contains '"+ existing.getcriteriaobject () +"'."); }    }

MONGO in Java