How to Create Index With MongoDB 3 Java Driver

Sample Java Program to Create Index in MongoDB 3 Java Driver . This snipped also contains older code which was used to create index . You just need to create a BasicDBObject with key as a name on which you want to create a index , and value will be 1 or -1 . if you create it with 1 then it will create a ascending index , and if you create with -1 , then it will create descending index .

package mongoDBExample;

import java.util.Arrays;
import java.util.List;

import org.bson.Document;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import com.mongodb.client.ListIndexesIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;

public class MongoDBTest
{
 public static void main(String[] args)
 {
  MongoClient mongoClient = new MongoClient(new MongoClientURI("mongodb://localhost:27017"));
  
  /*MongoDatabase database = mongoClient.getDatabase("Test");
  List books = Arrays.asList(1251,2512);
  Document person = new Document("_id", "ABHSIHEK")
                              .append("name", "java roots")
                              .append("address", new BasicDBObject("street", "sad java")
                                                           .append("city", "mongos")
                                                           .append("state", "mongod")
                                                           .append("zip", 5151))
                              .append("books", books);
  
  MongoCollection collection= database.getCollection("people");
     collection.insertOne(person);*/
  
  MongoDatabase database = mongoClient.getDatabase("Test");
  MongoCollection collection= database.getCollection("people");
  //create index on name field 
                //use 1 for ascending index , -1 for descending index 
  BasicDBObject index = new BasicDBObject("name",1);
  
  collection.createIndex(index);
  System.out.println(" index created successfully ");
  ListIndexesIterable indexes = collection.listIndexes(BasicDBObject.class);
  MongoCursor cursor = indexes.iterator();
  while(cursor.hasNext())
  {
   BasicDBObject getCreatedIdx = cursor.next();
   System.out.println("index is : "+ getCreatedIdx.toString());
  }
  
  
  
  mongoClient.close();
  /**
   * Older code which is deprecated in 3.0
   */
  /*
  DB db = mongoClient.getDB("Test");
  List books = Arrays.asList(27464, 747854);
  DBObject obj = new BasicDBObject("_id", "javaroots").append("name", "java roots")
                .append("address", new BasicDBObject("street", "awesome java")
                .append("city", "mongos")
                .append("state", "mongod")
                .append("zip", 5151))
.append("books", books);;
  
  DBCollection col = db.getCollection("people");
  col.insert(obj);
                col.createIndex("name");*/
        
  
 }
}

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