Examples of com.mongodb.DBCursor

com.mongodb.DBCursor
An iterator over database results. Doing a find() query on a collection returns a DBCursor thus
```
 DBCursor cursor = collection.find( query ); if( cursor.hasNext() ) DBObject obj = cursor.next(); 
```
Warning: Calling toArray or length on a DBCursor will irrevocably turn it into an array. This means that, if the cursor was iterating over ten million results (which it was lazily fetching from the database), suddenly there will be a ten-million element array in memory. Before converting to an array, make sure that there are a reasonable number of results using skip() and limit().
For example, to get an array of the 1000-1100th elements of a cursor, use
```
 List obj = collection.find( query ).skip( 1000 ).limit( 100 ).toArray(); 
```
@dochub cursors

        //collection.drop();
        return collection;
    }


    private static void printCollection(final DBCollection collection) {
        DBCursor cursor = collection.find().sort(new BasicDBObject("_id", 1));
        try {
            while (cursor.hasNext()) {
                System.out.println(cursor.next());
            }
        } finally {
            cursor.close();
        }


    }

View Full Code Here

        DB db = client.getDB("course");
        db.setReadPreference(ReadPreference.primary());
        DBCollection coll = db.getCollection("write.test");
        coll.setReadPreference(ReadPreference.primaryPreferred());


        DBCursor cursor = coll.find().setReadPreference(ReadPreference.nearest());
        try {
            while (cursor.hasNext()) {
                System.out.println(cursor.next());
            }
        } finally {
            cursor.close();
        }
    }

View Full Code Here

    public static void main(String[] args) throws UnknownHostException {
        MongoClient mongoClient = new MongoClient();
        DB school = mongoClient.getDB("school");
        DBCollection studentsCollection = school.getCollection("students");


        DBCursor students = studentsCollection.find();


        DBObject student = null;
        while(students.hasNext()) {
            student = students.next();


            List<DBObject> scores = (List<DBObject>)student.get("scores");


            DBObject lowestScore = null;

View Full Code Here

        return post;
    }


    public List<DBObject> findByDateDescending(int limit) {
        List<DBObject> posts;
        DBCursor cursor = postsCollection.find().sort(new BasicDBObject().append("date", -1)).limit(limit);
        try {
            posts = cursor.toArray();
        } finally {
            cursor.close();
        }
        return posts;
    }

View Full Code Here


    public List<DBObject> findByTagDateDescending(final String tag) {
        List<DBObject> posts;
        BasicDBObject query = new BasicDBObject("tags", tag);
        System.out.println("/tag query: " + query.toString());
        DBCursor cursor = postsCollection.find(query).sort(new BasicDBObject().append("date", -1)).limit(10);
        try {
            posts = cursor.toArray();
        } finally {
            cursor.close();
        }
        return posts;
    }

View Full Code Here

        return post;
    }


    public List<DBObject> findByDateDescending(int limit) {
        List<DBObject> posts;
        DBCursor cursor = postsCollection.find().sort(new BasicDBObject().append("date", -1)).limit(limit);
        try {
            posts = cursor.toArray();
        } finally {
            cursor.close();
        }
        return posts;
    }

View Full Code Here


    public List<DBObject> findByTagDateDescending(final String tag) {
        List<DBObject> posts;
        BasicDBObject query = new BasicDBObject("tags", tag);
        System.out.println("/tag query: " + query.toString());
        DBCursor cursor = postsCollection.find(query).sort(new BasicDBObject().append("date", -1)).limit(10);
        try {
            posts = cursor.toArray();
        } finally {
            cursor.close();
        }
        return posts;
    }

View Full Code Here

  }


  @Override
  public List<Message> getLastMessages() {
    DBCollection messagesCollection = chatDatabase.getCollection("historymessages");
    DBCursor curs = messagesCollection.find();


    List<Message> messages = new ArrayList<>();
    while (curs.hasNext()) {
      DBObject o = curs.next();
      String test = o.get("message").toString();
      Gson gson = new Gson();
      Message message = gson.fromJson(test, Message.class);
      messages.add(message);
    }

View Full Code Here

  public void onlyTenMessages() {
    DBCollection messagesCollection = chatDatabase.getCollection("historymessages");
    long nbMessages = messagesCollection.count();
    while (nbMessages > 10) {
      // enregistrement le plus vieux
      DBCursor oldestMessage = messagesCollection.find().sort(new BasicDBObject("date", 1)).limit(1);
      messagesCollection.remove(oldestMessage.next());
      nbMessages = messagesCollection.count();
    }


  }

View Full Code Here

    MessagesHistoryMongo conect = new MessagesHistoryMongo();


    DBCollection messagesCollection = chatDatabase.getCollection("historymessages");
    
    Long numberOfMessages = messagesCollection.count();
    DBCursor curs = messagesCollection.find();
    List<Message> messages = new ArrayList<>();
    while (curs.hasNext()) {
      DBObject o = curs.next();
      String test=o.get("message").toString();
      Gson gson = new Gson();
      Message message = gson.fromJson(test, Message.class);      
      messages.add(message);
    }
  
    Assert.assertEquals(new Long(10), numberOfMessages);
    Assert.assertEquals(new Date(1394743482).toString(),messages.get(0).getDate());
    
    Message message11 = new Message();
    message11.setMessage("un best OF!");
    message11.setUserFrom(new User("antho", Statut.EN_LIGNE, "192.168.1.3"));
    message11.setUserTo("all");
    message11.setEvent(Event.ALL_CLIENTS);
    message11.setDate(new Date(1395621082).toString());


    conect.saveMessage(message11);
    Long numberOfMessagesNew = messagesCollection.count();
    Assert.assertEquals(new Long(10), numberOfMessagesNew);
    
    DBCursor cursNew = messagesCollection.find();
    List<Message> messagesNew = new ArrayList<>();
    while (cursNew.hasNext()) {
      DBObject o = cursNew.next();
      String objectMessageNew=o.get("message").toString();
      Gson gson = new Gson();
      Message messageNew = gson.fromJson(objectMessageNew, Message.class);      
      messagesNew.add(messageNew);
    }

View Full Code Here

0 1 2 3 4 5 6 7 8 9

TOP

Related Classes of com.mongodb.DBCursor

avrobase.mongodb.MongoAB

ch.agent.crnickl.mongodb.ReadMethodsForChroniclesAndSeries

ch.agent.crnickl.mongodb.WriteMethodsForSchema

com.alvazan.orm.layer9z.spi.db.mongodb.CursorKeysToRowsMDB

com.bazaarvoice.commons.data.dao.mongo.AbstractMongoCriteriaDAO

com.bazaarvoice.commons.data.dao.mongo.AbstractMongoDAO

com.deftlabs.lock.mongo.impl.LockDao

com.edgytech.umongo.CollectionPanel

com.findwise.hydra.mongodb.MongoPipelineReader

com.github.jmkgreen.morphia.query.QueryImpl

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.