SpringBoot整合Apache Pulsar教程示例

# 使用 Spring Initializr 创建一个基本的 SpringBoot 项目
$ curl https://start.spring.io/starter.zip -d dependencies=web -d language=java -d javaVersion=1.8 -d bootVersion=2.6.3 -o demo.zip
$ unzip demo.zip

<dependency>
    <groupId>org.apache.pulsar</groupId>
    <artifactId>pulsar-client</artifactId>
    <version>2.7.1</version>
</dependency>

import org.apache.pulsar.client.api.Producer;
import org.apache.pulsar.client.api.PulsarClient;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
@Component
public class PulsarProducer {
    private Producer<String> producer;
    @PostConstruct
    public void init() throws Exception {
        // 创建 Pulsar 客户端
        PulsarClient client = PulsarClient.builder()
                .serviceUrl("pulsar://localhost:6650")
                .build();
        // 创建消息生产者
        producer = client.newProducer(Schema.STRING)
                .topic("persistent://public/default/my-topic")
                .create();
    }
    public void send(String message) throws Exception {
        // 发送消息
        producer.send(message);
    }
    @PreDestroy
    public void close() throws Exception {
        // 关闭消息生产者
        producer.close();
    }
}

import org.apache.pulsar.client.api.Consumer;
import org.apache.pulsar.client.api.Message;
import org.apache.pulsar.client.api.MessageListener;
import org.apache.pulsar.client.api.PulsarClient;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
@Component
public class PulsarConsumer
        implements MessageListener<String>
{
    private Consumer<String> consumer;
    @PostConstruct
    public void init()
            throws Exception
    {
        // 创建 Pulsar
        PulsarClient client = PulsarClient.builder()
                .serviceUrl("pulsar://localhost:6650")
                .build();
// 创建消息消费者
        consumer = client.newConsumer(Schema.STRING)
                .topic("persistent://public/default/my-topic")
                .subscriptionName("my-subscription")
                .messageListener(this)
                .subscribe();
    }
    @Override
    public void received(Consumer<String> consumer, Message<String> message)
    {
        try {
            // 处理消息
            System.out.println("Received message: " + message.getValue());
            // 标记消息已被消费
            consumer.acknowledge(message);
        }
        catch (Exception e) {
            // 处理异常
            consumer.negativeAcknowledge(message);
        }
    }
    @PreDestroy
    public void close()
            throws Exception
    {
        // 关闭消息消费者
        consumer.close();
    }
}

@RestController
public class HelloController {
    @Autowired
    private PulsarProducer producer;
    @Autowired
    private PulsarConsumer consumer;
    @GetMapping("/send")
    public String send() {
        try {
            // 发送消息
            producer.send("Hello, Pulsar!");
            return "Send message success.";
        } catch (Exception e) {
            return "Send message failed.";
        }
    }
}