driver-legacy/src/main/com/mongodb/DBCollection.java
public void dropIndex(final DBObject index) {
        try {
            executor.execute(new DropIndexOperation(getNamespace(), wrap(index), getWriteConcern()), getReadConcern());
        } catch (MongoWriteConcernException e) {
            throw createWriteConcernException(e);
        }
    }
public void dropIndex(final DBObject index) {
        try {
            executor.execute(new DropIndexOperation(getNamespace(), wrap(index), getWriteConcern()), getReadConcern());
        } catch (MongoWriteConcernException e) {
            throw createWriteConcernException(e);
        }
    }
public void dropIndex ( final DBObject index ) { try { executor . execute ( new DropIndexOperation ( getNamespace ( ) , wrap ( index ) , getWriteConcern ( ) ) , getReadConcern ( ) ) ; } catch ( MongoWriteConcernException e ) { throw createWriteConcernException ( e ) ; } }
Drops an index from this collection.  The DBObject index parameter must match the specification of the index to drop, i.e. correct
key name and type must be specified.

@param index the specification of the index to drop
@throws MongoException if the index does not exist
@mongodb.driver.manual core/indexes/ Indexes
Drops an index from this collection . The DBObject index parameter must match the specification of the index to drop i . e . correct key name and type must be specified .