I trying to connect server but I am getting this error

Error
_com.mongodb.MongoTimeoutException:
Timed out after 3000 ms while waiting to connect. Client view of cluster state is
{type=UNKNOWN,
servers=[{
address=<server_address>:27017,
type=UNKNOWN,
state=CONNECTING,
exception=

{ com.mongodb.MongoException: java.lang.NoClassDefFoundError: com.mongodb.connection.ScramSha1Authenticator$ScramSha1SaslClient }

,
caused by

{java.lang.NoClassDefFoundError: com.mongodb.connection.ScramSha1Authenticator$ScramSha1SaslClient}

}]_

This is my Code:
_MongoClientOptions.Builder o = MongoClientOptions.builder().serverSelectionTimeout(3000);
MongoCredential credential = MongoCredential.createCredential("admin", "<database_name>","admin".toCharArray());

// Creating a Mongo client
MongoClient mongo = new MongoClient( new ServerAddress("<server_address>" , 27017),credential,o.build());

System.out.println("Connected to the database successfully ");

// Accessing the database
MongoDatabase database = mongo.getDatabase("<database_name>");
System.out.println("Collection created successfully");
// Retrieving a collection
MongoCollection<Document> collection = database.getCollection("<collection_name>");
System.out.println("Collection sampleCollection selected successfully ");

//Getting the iterable object
FindIterable<Document> iterDoc = collection.find();
int i = 1;

String s = null;
// Getting the iterator
Iterator it = null;
try {
it = iterDoc.iterator();
while (it.hasNext())

{ System.out.println(it.next()); s+=it.next().toString(); i++; }

} catch (Exception e)

{ e.printStackTrace(); Log.i("TAG",""+e); }

return s;_