BE THE CODER > No SQL > Mongo DB Examples > How to drop index on Collection

MongoDB is a scalable, high-performance, open source NoSQL database. It offers Ad hoc queries, Indexing, Replication, Load balancing, File storage (GridFS), Aggregation, MapReduce and Server-side JavaScript execution. This requires the library mongo-2.8.0.jar to be present in the classpath. The following example shows how to drop an Index on a Collection.

File Name :	com/bethecoder/tutorials/mongodb/tests/DropIndexTest.java
Author :	Sudhakar KV
Email :	[email protected]


package com.bethecoder.tutorials.mongodb.tests;



import java.net.UnknownHostException;

import java.util.List;



import com.mongodb.BasicDBObject;

import com.mongodb.DB;

import com.mongodb.DBCollection;

import com.mongodb.DBObject;

import com.mongodb.Mongo;

import com.mongodb.MongoException;



public class DropIndexTest {



  /**

   * @param args

   */

  public static void main(String[] args) {



    try {

      //Connect to mongoDB with given IP and PORT

      Mongo mongo = new Mongo("localhost", 27017);

      

      //Get the database object

      DB database = mongo.getDB("mytestdb");

      

      //Gets a collection with a given name.

      DBCollection collection = database.getCollection("students");

      

      //Show indexes

      showIndexes(collection);

      

      //Drops an index from this collection

      collection.dropIndex(new BasicDBObject("name", 1));

      collection.dropIndex(new BasicDBObject("age", -1));

      

      System.out.println();

      System.out.println();

      

      //Show indexes

      showIndexes(collection);

          

    } catch (UnknownHostException e) {

      e.printStackTrace();

    } catch (MongoException e) {

      e.printStackTrace();

    }

  }

  

  private static void showIndexes(DBCollection collection) {

    //Get List of Indexes on a Collection

    List<DBObject> indexes = collection.getIndexInfo();



        for (DBObject o : indexes) {

            System.out.println(o);

        }

  }

}