kafka动态接口topic信息

1、监听配置

package *************.listener;
import cn.hutool.extra.spring.SpringUtil;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.kafka.config.KafkaListenerContainerFactory;
import org.springframework.kafka.config.MethodKafkaListenerEndpoint;
import org.springframework.kafka.listener.ConcurrentMessageListenerContainer;
import org.springframework.kafka.listener.MessageListener;
import org.springframework.kafka.config.KafkaListenerEndpointRegistry;
import org.springframework.messaging.handler.annotation.support.DefaultMessageHandlerMethodFactory;
import org.springframework.stereotype.Service;
import java.lang.reflect.Method;
import java.util.List;

@Service
public class KafkaListenerService {
    @Autowired
    @Qualifier("kafkaListenerService")
    private KafkaListenerEndpointRegistry registry;
    @Autowired
    private KafkaMessageHandlerService kafkaMessageHandlerService;
    public void addListener(String topic, String groupId) throws NoSuchMethodException {
        String id = topic + "-" + groupId;
        if (registry.getListenerContainer(id) != null) {
            System.out.println("Listener already exists for topic: " + topic + " and group: " + groupId);
            return;
        }
        MethodKafkaListenerEndpoint<String, String> endpoint = new MethodKafkaListenerEndpoint<>();
        //设置监听器端点相关信息
        //设置Id
        endpoint.setId(id);
        //设置消费者组
        endpoint.setGroupId(groupId);
        //设置要监听的topic数组，可以是多个
        endpoint.setTopics(topic);
        //设置每个监听器线程数
        endpoint.setConcurrency(1);
        //设置批量监听
        endpoint.setBatchListener(true);
        //设置消息处理工厂类，这里用的是默认工厂
        endpoint.setMessageHandlerMethodFactory(new DefaultMessageHandlerMethodFactory());
        //设置实际处理的Bean对象，即实际的对象，比如new Class();
        endpoint.setBean(kafkaMessageHandlerService);
        //设置实际处理的方法(包含方法名和参数)
        Method method = KafkaMessageHandlerService.class.getDeclaredMethod("handleMessage", List.class);
        endpoint.setMethod(method);
        //注册Container并启动，startImmediately表示立马启动
        registry.registerListenerContainer(endpoint, SpringUtil.getBean(KafkaListenerContainerFactory.class), true);
        System.out.println("Added listener for topic: " + topic + " and group: " + groupId);
    }

}

2、初始化监听

方法一：放代码中 项目启动加载相关的config调用，相关的topic可以维护在数据库中，启动查询遍历初始化public void createKafkaListener(String topic){
        log.info("初始化topic信息topic:{}",topic);
        try {
            kafkaListenerService.addListener(topic, Const.ALARM_GROUP);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        }
    }

方法二：放启动类里面固定tpoic用来方便测试

@SpringBootApplication
@MapperScan(value = {"com.aaa.aaa.module.aaa.dal.mapper.*"})
public class Application {
    public static void main(String[] args) throws NoSuchMethodException {
        SpringApplication.run(Application.class, args);
        ConfigurableApplicationContext context = SpringApplication.run(Application.class, args);
        KafkaListenerService kafkaListenerService = context.getBean(KafkaListenerService.class);
        kafkaListenerService.addListener("testTopic", "testGroup");
        System.out.printf("开启");
    }
3、接收到Kafka消息

package com.inspur.industry.module.alarm.listener;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONArray;
import cn.hutool.json.JSONUtil;
import com.alibaba.fastjson2.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.stereotype.Service;
import java.util.List;
@Slf4j
@Service
public class KafkaMessageHandlerService {

    public void handleMessage(List<ConsumerRecord<String, Object>> records) {
        log.info("kafka收到消息records:{}", records);
        for (ConsumerRecord<String, Object> record : records) {
            // 打印消息的内容和元数据
//            System.out.println("Received Message: " + record.value());
//            System.out.println("Topic: " + record.topic());
//            System.out.println("Partition: " + record.partition());
//            System.out.println("Offset: " + record.offset());
            String recordValue = (String) record.value();
            log.info("kafka消息转换为recordValue:{}", recordValue);
           parse(recordValue.toString());
        }
    }
    /**
     * @param recordValue 业务数据
     */
    private void parse(String recordValue) {
        log.info("进入parseAlarmRules()方法,recordValue:" + recordValue);
        //将收到的业务数据转换成JSON对象
        JSONObject valueObject = JSONObject.parseObject(recordValue);
        log.info("将接收到的数据转换为valueObject");
        //具体业务逻辑处理
    }
}
注意：初始化监听非常重要，如果不初始化监听，就会接收不到Kafka消息

具体的Kafka配置和发送，前面文章已经提及，可以参考前面文章，不在叙述