Rocketmq Client 3.6.2.final version analysis in the Java class library
Rocketmq Client 3.6.2.final version analysis in the Java class library
Abstract: This article will analyze the Rocketmq Client 3.6.2.final version in the Java class library to introduce its main characteristics and usage, and provide some Java code examples.
introduction:
RocketMQ is a distributed message queue system developed by Alibaba Group to achieve reliable message transmission.RocketMQ Client is the Java client library of RocketMQ, which provides convenient API for using RocketMQ in Java applications.
RocketMQ Client Main features:
1. Support synchronization and asynchronous message sending: RocketMQ Client provides synchronous and asynchronous message sending methods to meet different application needs.
2. Support order message: RocketMQ Client can send and receive sequential messages to ensure the order of message.
3. Provide message filtering mechanism: Rocketmq Client supports a message filtering mechanism based on the SQL92 expression, which can be filtered according to the attribute of the message.
4. Support transaction message: RocketMQ Client provides support of transaction messages to ensure the consistency of distributed transactions.
5. Support message trajectory: RocketMQ Client provides message trajectory function, which can track the transmission path of message in the system.
6. Support delay message: RocketMQ Client allows sending delay messages to meet some scenes that need to be delayed.
Example of RocketMQ Client:
Here are some example code, which shows the basic usage of RocketMQ Client:
1. Create producers:
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.common.message.Message;
public class RocketMQProducer {
public static void main(String[] args) throws Exception {
DefaultMQProducer producer = new DefaultMQProducer("group");
producer.setNamesrvAddr("localhost:9876");
producer.start();
Message message = new Message("topic", "tag", "Hello, RocketMQ".getBytes());
producer.send(message);
producer.shutdown();
}
}
2. Create consumers:
import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.common.message.MessageExt;
import java.util.List;
public class RocketMQConsumer {
public static void main(String[] args) throws Exception {
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("group");
consumer.setNamesrvAddr("localhost:9876");
consumer.subscribe("topic", "*");
consumer.registerMessageListener((MessageListenerConcurrently) (messages, context) -> {
for (MessageExt message : messages) {
System.out.println(message);
}
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
});
consumer.start();
}
}
in conclusion:
RocketMQ Client 3.6.2.final version is a functional Java client library that provides various messages and features.Through the above examples, we can initially understand how to use RocketMQ Client in Java applications.
