amazon-web-services - AWS SNS notification are not sent

Question

I am using AWS SDK to send SNS, but notification are not going out.

final AmazonSNSClient client = new AmazonSNSClient( new BasicAWSCredentials( "xxxx", "zzzzzzzzzzzz") );
final PublishRequest request = new PublishRequest("arn:aws:sns:us-east-1:123455:DEV_WEBSERVICE_ERROR", "This is test", "DEV-Publish");
final PublishResult result = client.publish( request );
System.out.println(result.getMessageId());
client.shutdown();

I have created a topic and arn is mentioned in the request. When I execute this code, it does no send out notification.

Please let me know, what wrong is going there.I am using AWS JAVA SDK 1.5.6

-Thanks Subhash