The introduction and usage guide of the Rabbitmq framework in the Java library
The introduction and usage guide of the Rabbitmq framework in the Java library
Overview:
Rabbitmq is a powerful and reliable open source message proxy software for enterprise -level message queues.It is based on the AMQP (Advanced Message Questing Agreement) standard and provides a flexible message transmission mode to help developers build scalable distributed applications.
Core concept of rabbitmq:
1. Producer (producer): Create and send messages to the queue.
2. Consumer (consumer): receive and process the message from the queue.
3. Queue (queue): container for storing messages.
4. Exchange (switch): receive messages from producers and distribute the message to the matching queue.
5. Binding (binding): defines the association rules between switches and queues.
Use Rabbitmq in the Java library:
The following are the basic steps to use Rabbitmq in Java:
Step 1: Install and start Rabbitmq
First, you need to install Rabbitmq and start it.You can download and install a version suitable for your operating system from the official website of Rabbitmq.
Step 2: Import Rabbitmq Java class library
Import Rabbitmq Java libraries in the construction path of the Java application to use the class and methods in it.
Step 3: Create a connection and channel
Use the ConnectionFactory class to create a connection with the RabbitMQ server.Then use the Connection object to create a Channel (channel) object, which will be used to interact with Rabbitmq.
Example code:
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;
public class RabbitMQExample {
private final static String QUEUE_NAME = "my_queue";
public static void main(String[] argv) throws Exception {
ConnectionFactory factory = new ConnectionFactory();
Factory.setHost ("Localhost"); // Set the host of the RabbitMQ server
Factory.setUsername ("guest"); // Set the user name of accessing Rabbitmq
Factory.setPassword ("guest"); // Set the password of access to Rabbitmq
Connection connection = factory.newConnection();
Channel channel = connection.createChannel();
// Next, you can declare a queue, define switch, binding queue and switch association on the channel
}
}
Step 4: Send message to the queue
Use the channel's `BasicPublish` method to send messages to the queue.You need to specify parameters such as switch names, routing keys, message body.
Example code:
channel.basicPublish("", QUEUE_NAME, null, "Hello RabbitMQ!".getBytes());
Step 5: Receive and process messages
Use the callback method based on the `Consumer` to consumer queue.Define a class inherited from DefaultConsumer, and rewrite the `handledelivery` method to process the received messages.
Example code:
channel.basicConsume(QUEUE_NAME, true, new DefaultConsumer(channel) {
@Override
public void handleDelivery(String consumerTag, Envelope envelope,
AMQP.BasicProperties properties, byte[] body) throws IOException {
String message = new String(body, "UTF-8");
System.out.println("Received message: " + message);
}
});
This is the basic step of sending and receiving messages using the Rabbitmq framework in Java.Of course, Rabbitmq also provides more advanced features, such as the persistence of messages, message confirmation mechanisms, message priority, etc.
Summarize:
Rabbitmq is a functional and easy -to -use distributed message queue framework, which is suitable for building scalable applications.It only takes a few simple steps to use Rabbitmq in the Java library to achieve message sending and receiving.I hope this article will help you understand the basic use and concept of the Rabbitmq framework.
