RABBITMQ Study First: Connect with Java RABBITMQ

1. What is RABBITMQ

MQ (Message Queue): A queue of messages that is designed by the server to store a large number of messages and provides a way for the client to operate the queue: the production queue (adding data to the queue), the consumption queue (fetching data from the queue). RABBITMQ is a typical application based on Message Queuing. RABBITMQ In addition to the normal production and consumption functions, there are some advanced features: Fair distribution, polling distribution, routing mode, wildcard mode, publish subscription, queue persistence.

2, Java implementation of RABBITMQ connection

2.1. RABBITMQ Client Jar Package

<dependency>
<groupId>com.rabbitmq</groupId>
<artifactId>amqp-client</artifactId>
<version>4.0.2</version>
</dependency>

2.2. Java Connection RABBITMQ Tool class

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public class Connectionutil
{
private static Logger Logger = Logger.getlogger (Connectionutil.class);

public static Connection getConnection(){    try    {        Connection connection = null;        //定义一个连接工厂        ConnectionFactory factory = new ConnectionFactory();        //设置服务端地址（域名地址/ip）        factory.setHost("127.0.0.1");        //设置服务器端口号        factory.setPort(5672);        //设置虚拟主机(相当于数据库中的库)        factory.setVirtualHost("/");        //设置用户名        factory.setUsername("admin");        //设置密码        factory.setPassword("888888");        connection = factory.newConnection();        return connection;    }    catch (Exception e)    {        return null;    }}

}
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2.3. Simple producer-consumer model

Work map taken from the production and consumption model of the official website (RabbitMQ)

P: Producer of messages

C: Consumer of the message

Red: Queue

The producer sends the message to the queue and the consumer gets the message from the queue.

2.4. Producer (Send)

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public class Send
{
Queue name
private static final String queue_name = "Test_simple_queue";

public static void main(String[] args){    try    {        //获取连接        Connection connection = ConnectionUtil.getConnection();        //从连接中获取一个通道        Channel channel = connection.createChannel();        //声明队列        channel.queueDeclare(QUEUE_NAME, false, false, false, null);        String message = "This is simple queue";        //发送消息        channel.basicPublish("", QUEUE_NAME, null, message.getBytes("utf-8"));        System.out.println("[send]：" + message);        channel.close();        connection.close();    }    catch (IOException | TimeoutException e)    {        e.printStackTrace();    }}

}

Operation Result:
[Send]:this is simple queue
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2.5. Consumer (Receive)

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public class Receive
{
Queue name
private static final String queue_name = "Test_simple_queue";

public static void main(String[] args){    try    {        //获取连接        Connection connection = ConnectionUtil.getConnection();        //从连接中获取一个通道        Channel channel = connection.createChannel();        //声明队列        channel.queueDeclare(QUEUE_NAME, false, false, false, null);        //定义消费者        DefaultConsumer consumer = new DefaultConsumer(channel)        {            //当消息到达时执行回调方法            @Override            public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties,                    byte[] body) throws IOException            {                String message = new String(body, "utf-8");                System.out.println("[Receive]：" + message);            }        };        //监听队列        channel.basicConsume(QUEUE_NAME, true, consumer);    }    catch (IOException | ShutdownSignalException | ConsumerCancelledException e)    {        e.printStackTrace();    }}

}

Operation Result:
[Receive]:this is simple queue
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Summary :
The simple producer-consumer model enables producers to produce data in the queue, and the consumer can listen to the queue continuously and fetch data from the queue.

RABBITMQ Study First: Connect with Java RABBITMQ