jestrel

Simple Java client for Kestrel

Motivation

Working with Kestrel queues should be easy. But after scouring the web, I couldn't find a "native" Kestrel client for Java, only some memcached clients that had some support for Kestrel-specific stuff.

So, building on top of the xmemcached library on googlecode, I wrote jestrel

System Requirements

• Java 7
• Maven 3

Building

mvn package

Usage

Initialize the client library

// Setup configuration
Properties kestrelProperties = new Properties();

// Max # of connections to kestrel. default is 1
kestrelProperties.setProperty("kestrelConnectionPoolSize", "10");

// Comma-separated list of hostname:port of all kestrel servers to use. required.
kestrelProperties.setProperty("kestrelHosts", "kestrel-1:22133, kestrel-2:22133");

// How often should the client drop its connection to kestrel and reconnect. default is 5 minutes
// If you are using multiple kestrel servers, this will ensure that no kestrel server sits idle with no clients
kestrelProperties.setProperty("kestrelReconnectIntervalInMinutes", "5");

// Create a client
MqClientFactory clientFactory = new MqClientFactory();
MqClient client = clientFactory.createClient(KestrelClient.class, kestrelProperties);

Sending a message

String queueName = "some_queue";
MqProducer producer = client.getProducer(queueName);
producer.send("some message");

Registering a queue consumer

// I'm using an inline class here for brevity.
// You will probably want to create your own class that implements the MqConsumer interface.
MqConsumer consumer = new MqConsumer() {
    /**
     * @param o The message, which will be a String
     * @exception Exception If any exception is thrown, the message will be put onto the errorQueue (unless it was set to null when the consumer was registered)
     */
    public void onMessage(Object o) throws Exception {
        System.out.println("received: " + o.toString());
    }
};

String queueName = "some_queue";
String errorQueueName = "some_queue_error";

client.registerConsumer(consumer, queueName, errorQueueName);