Loveflowers/JavaNSQClient: Fast Java client for NSQ · GitHub

<dependency>
  <groupId>com.github.brainlag</groupId>
  <artifactId>nsq-client</artifactId>
  <version>1.0.0.RC1</version>
</dependency>

NSQLookup lookup = new NSQLookup();
lookup.addAddr("localhost", 4161);
NSQConsumer consumer = new NSQConsumer(lookup, "speedtest", "dustin", (message) -> {
        System.out.println("received: " + message);            
        //now mark the message as finished.
        message.finished();
        
        //or you could requeue it, which indicates a failure and puts it back on the queue.
        //message.requeue();
});
        
consumer.start();

NSQProducer producer = new NSQProducer().addAddress("localhost", 4150).start();            
producer.produce("TestTopic", ("this is a message").getBytes());

consumer.setExecutor(...);