How to use the RabbitMQ Scala client to process messages in the Java class library
How to use the RabbitMQ Scala client to process messages in the Java class library
Rabbitmq is a popular message agent to build distributed applications and microservice architectures.It uses a message queue to ensure reliable communication between applications.Rabbitmq offers a variety of client libraries, including the Scala client, which can easily integrate with the Java class library.
This article will introduce how to use the RabbitMQ Scala client to process messages in the Java library.Here are some steps and examples to help you start using Rabbitmq.
Step 1: Install Rabbitmq
First, you need to install the RabbitMQ message agent.You can download and install Rabbitmq from Rabbitmq's official website (https://www.rabbitmq.com/).
Step 2: Add Maven dependency
In order to use the RabbitMQ Scala client, you need to add the following Maven dependency items to your project's pom.xml file:
<dependency>
<groupId>com.rabbitmq</groupId>
<artifactId>amqp-client_2.13</artifactId>
<version>5.12.0</version>
</dependency>
Step 3: Create Rabbitmq connection
Using Rabbitmq in the Java library, you first need to create a connection connected to the RabbitMQ server.The following is a sample code to create RabbitMQ connection:
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class RabbitMQConnection {
public static Connection getConnection() throws Exception {
ConnectionFactory factory = new ConnectionFactory();
Factory.setHost ("LocalHost"); // Rabbitmq server address
Factory.setUsername ("Guest"); // Rabbitmq user name
Factory.setPassword ("guest"); // Rabbitmq password
Connection connection = factory.newConnection();
return connection;
}
}
Step 4: Send message
Next, you can use RabbitMQ to connect to create a channel and post messages to the specified queue through the channel.The following is a sample code to send a message to the Rabbitmq queue:
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
public class MessageSender {
public static void sendMessage(String queueName, String message) throws Exception {
Connection connection = RabbitMQConnection.getConnection();
Channel channel = connection.createChannel();
Channel.queueDeclare (queuename, false, false, false, null); // Declarize the queue
Channel.basicpublish ("", Queuename, NULL, MESSAGE.Getbytes ()); // Post a message to the queue to queue
channel.close();
connection.close();
}
}
Step 5: Receive message
You can use RabbitMQ to connect to create a channel and use messages in the specific queue of the channel.The following is a sample code to receive the message in the Rabbitmq queue:
import com.rabbitmq.client.*;
public class MessageReceiver {
public static void receiveMessage(String queueName) throws Exception {
Connection connection = RabbitMQConnection.getConnection();
Channel channel = connection.createChannel();
Channel.queueDeclare (queuename, false, false, false, null); // Declarize the queue
channel.basicConsume(queueName, 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);
}
});
}
}
The above example code creates a consumer object and subscribe to the specified queue by `Channel.BasicConsume ()` `method.When the news arrives, the method of `handledelivery ()` will be called and printed the received messages.
Through the above steps, you can use the Rabbitmq Scala client in the Java library to process messages.The sender can use the `MessageSender` class to send messages, and the receiver can use the` MessageReceiver` class to receive the message.
