How to limit the number of records, while retrieving data from a MongoDB collection using Java?

While retrieving records from a MongoDB collection, you can limit the number of records in the result using the

limit() method.

Syntax

db.COLLECTION_NAME.find().limit(no.of records needed)

The Java MongoDB library provides a method with the same name, to limit the number of records invoke this method (on the result of the find() method) by passing an integer value representing the required number of records.

Example

import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.bson.Document;
import com.mongodb.MongoClient;
public class LimitingRecords {
   public static void main( String args[] ) {
      //Creating a MongoDB client
      MongoClient mongo = new MongoClient( "localhost" , 27017 );
      //Connecting to the database
      MongoDatabase database = mongo.getDatabase("myDatabase");
      //Creating a collection object
      MongoCollection<Document>collection = database.getCollection("students");
      Document document1 = new Document("name", "Ram").append("age", 26).append("city", "Hyderabad");
      Document document2 = new Document("name", "Robert").append("age", 27).append("city", "Vishakhapatnam");
      Document document3 = new Document("name", "Rhim").append("age", 30).append("city", "Delhi");
      Document document4 = new Document("name", "Radha").append("age", 28).append("city", "Mumbai");
      Document document5 = new Document("name", "Ramani").append("age", 45).append("city", "Pune");
      //Inserting the created documents
      List<Document> list = new ArrayList<Document>();
      list.add(document1);
      list.add(document2);
      list.add(document3);
      list.add(document4);
      list.add(document5);
      collection.insertMany(list);
      System.out.println("Documents Inserted");
      //Retrieving a collection object
      collection = database.getCollection("students");  
      //Retrieving the documents with a limit
      FindIterable<Document> iterDoc = collection.find().limit(3);
      Iterator it = iterDoc.iterator();
      while (it.hasNext()) {
         System.out.println(it.next());
      }

   }
}

Output

Documents Inserted
Document{{_id=5e887b16dac53c7f07cfd740, name=Ram, age=26, city=Hyderabad}}
Document{{_id=5e887b16dac53c7f07cfd741, name=Robert, age=27, city=Vishakhapatnam}}
Document{{_id=5e887b16dac53c7f07cfd742, name=Rhim, age=30, city=Delhi}}

Krishna Kasyap

Published on 10-Apr-2020 10:51:01