{"id":24188,"date":"2015-07-28T18:45:55","date_gmt":"2015-07-28T13:15:55","guid":{"rendered":"http:\/\/www.tothenew.com\/blog\/?p=24188"},"modified":"2015-07-29T16:30:24","modified_gmt":"2015-07-29T11:00:24","slug":"sending-scheduleddelayed-messages-with-rabbitmq-through-java-client","status":"publish","type":"post","link":"https:\/\/www.tothenew.com\/blog\/sending-scheduleddelayed-messages-with-rabbitmq-through-java-client\/","title":{"rendered":"Sending Scheduled\/delayed messages with RabbitMQ through java client"},"content":{"rendered":"

The requirement to send delayed\/scheduled message is to publish any message with a delay time. To achieve this, earlier we had to use dead letter exchange but now we can send scheduled\/delayed messages from RabbitMQ<\/a> with “rabbitmq_delayed_message_exchange” plugin. we can send scheduled\/ delayed messages from rabbitMQ by following these steps :-<\/p>\n

Step 1<\/strong>– Install rabbitMQ server to 3.5.3 or above on your machine. Follow this guide to install rabbitMQ http:\/\/www.rabbitmq.com\/download.html<\/a><\/p>\n

Step 2\u00a0<\/strong>– Download “rabbitmq_delayed_message_exchange” plugin from rabbitMQ official website. Follow this link to download “rabbitmq_delayed_message_exchange” http:\/\/www.rabbitmq.com\/community-plugins.html<\/a><\/p>\n

Step 3\u00a0<\/strong>– Place “rabbitmq_delayed_message_exchange” plugin into plugins directory of rabbitMQ server directory (in linux ‘\/usr\/lib\/rabbitmq\/lib\/rabbitmq_server-3.5.3\/plugins’ path)<\/p>\n

Step 4\u00a0<\/strong>– Execute “rabbitmq-plugins enable rabbitmq_delayed_message_exchange” command to enable “rabbitmq_delayed_message_exchange” plugin.<\/p>\n

Step 5\u00a0<\/strong>– Now, after configuring rabbitMQ server we are ready to send scheduled or delayed messages. To send scheduled message we have to declare an exchange with ‘x-delayed-message’ which is indirectly mapped with the any of the exchange types i.e topic,direct,fanout or headers.
\nFollow this code to publish message to delayed exchange:-<\/p>\n

[java]
\n String readyToPushContent = "Hello this is the delayed message.";<\/p>\n

Map<String, Object> args = new HashMap<String, Object>();
\n args.put("x-delayed-type", "direct");
\n channel.exchangeDeclare("exChangeName", "x-delayed-message", true, false, args);<\/p>\n

Map<String, Object> headers = new HashMap<String, Object>()
\n headers.put("x-delay", 10000); \/\/delay in miliseconds i.e 10secs<\/p>\n

AMQP.BasicProperties.Builder props = new AMQP.BasicProperties.Builder().headers(headers);
\n channel.basicPublish("exChangeName", "", props.build(), readyToPushContent.bytes);<\/p>\n

[\/java]<\/p>\n

a.<\/strong> This plugin allows flexible routing behavior via “x-delayed-type” which can be passed at the time of\u00a0\u00a0exchange declaration. \u00a0i.e \u00a0this exchange will provide routing behavior like “direct” exchange, and exchange with type “x-delayed-message” will act as proxy.<\/p>\n

b.<\/strong> Here we declare an exchange with “x-delayed-message” type. Then we attach a header with “x-delay” at the time of publish message, \u00a0which accepts integer value \u00a0as time (in milliseconds).<\/p>\n

Step 6\u00a0<\/strong>– To Subscribe message from delayed exchange follow this code :-<\/p>\n

[java]
\n QueueingConsumer queueingConsumer = new QueueingConsumer(channel) \/\/ creating a consumer from channel<\/p>\n

Map<String, Object> args = new HashMap<String, Object>();
\n args.put("x-delayed-type", "direct");
\n channel.exchangeDeclare("exChangeName", "x-delayed-message", true, false, args); \/\/ declare delayed exchange<\/p>\n

String queueName = channel.queueDeclare().getQueue(); \/\/ declaring dynamic queue in channel<\/p>\n

channel.queueBind(queueName, "exChangeName", ""); \/\/ binding queue with delayed exchnage<\/p>\n

channel.basicConsume(queueName, true, queueingConsumer) \/\/ consuming message from queue in consumer object<\/p>\n

try {
\n QueueingConsumer.Delivery delivery = queueingConsumer.nextDelivery() \/\/ <\/p>\n

String message = (new String(delivery.getBody()))<\/p>\n

} catch (Exception exception) {
\n exception.printStackTrace()<\/p>\n

}
\n[\/java]<\/p>\n

Hope, this will help you to send scheduled\/delayed messages with rabbitMQ.
\nBouquets and brickbats are welcome.<\/p>\n

~vishal(d0t)kumar(at)tothenew(d0t)com~<\/p>\n","protected":false},"excerpt":{"rendered":"

The requirement to send delayed\/scheduled message is to publish any message with a delay time. To achieve this, earlier we had to use dead letter exchange but now we can send scheduled\/delayed messages from RabbitMQ with “rabbitmq_delayed_message_exchange” plugin. we can send scheduled\/ delayed messages from rabbitMQ by following these steps :- Step 1– Install rabbitMQ […]<\/p>\n","protected":false},"author":250,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":32,"footnotes":""},"categories":[7,446,1],"tags":[2049,4844,1077],"class_list":["post-24188","post","type-post","status-publish","format-standard","hentry","category-grails","category-java","category-technology","tag-gails","tag-java","tag-rabbitmq"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t