Accessing value from nested mongodb document

Question

How can I access value from key/value pair from the subdocument (Mongodb) using Java?

{ "_id" : { "key1" : "val1"} , "key2" : “val2” , "subdoc" : { "key3" : "val3" , "key4" : "val4" }

    DB db = (new MongoClient("localhost", 27017)).getDB("nov2014");         
    DBCollection dbCollection = db.getCollection("student");    

    BasicDBObject basicDBObj = new BasicDBObject();
    basicDBObj.put("key1", " val1");            

    DBCursor dbCursor = dbCollection.find(basicDBObj);          
    while(dbCursor.hasNext()){
        BasicDBObject dbObject = (BasicDBObject)dbCursor.next();    
        System.out.println(“Key 2: ” = dbObject.getString("key2");
        System.out.println(“Key 3: ” = dbObject.getString("subdoc.key3");
        System.out.println(“Key 4: ” = dbObject.getString("subdoc.key4");                           
    }

In the output values of key3 and key 4 are null. Can someone tell me how to access values from the subdocument?

Answer 1

Use the following code snippet please:

DB db = (new MongoClient("localhost", 27017)).getDB("nov2014");         
DBCollection dbCollection = db.getCollection("student");    

BasicDBObject basicDBObj = new BasicDBObject();
basicDBObj.put("key1", " val1");            

DBCursor dbCursor = dbCollection.find(basicDBObj);          
while(dbCursor.hasNext()){
    BasicDBObject dbObject = (BasicDBObject)dbCursor.next();    
    System.out.println(“Key 2: ” = dbObject.getString("key2");
    System.out.println(“Key 3: ” = ((BasicDBObject)dbObject.get("subdoc")).get("key3");
    System.out.println(“Key 4: ” = ((BasicDBObject)dbObject.get("subdoc")).get("key4");                         
}