本文介绍如何在springboot项目中集成kafka收发message。
1、先解决依赖
springboot相关的依赖我们就不提了，和kafka相关的只依赖一个spring-kafka集成包
org.springframework.kafka spring-kafka 1.1.1.RELEASE
这里我们先把配置文件展示一下
#============== kafka =================== kafka.consumer.zookeeper.connect=10.93.21.21:2181 kafka.consumer.servers=10.93.21.21:9092 kafka.consumer.enable.auto.commit=true kafka.consumer.session.timeout=6000 kafka.consumer.auto.commit.interval=100 kafka.consumer.auto.offset.reset=latest kafka.consumer.topic=test kafka.consumer.group.id=test kafka.consumer.concurrency=10 kafka.producer.servers=10.93.21.21:9092 kafka.producer.retries=0 kafka.producer.batch.size=4096 kafka.producer.linger=1 kafka.producer.buffer.memory=40960
2、Configuration：Kafka producer
1）通过@Configuration、@EnableKafka，声明Config并且打开KafkaTemplate能力。
2）通过@Value注入application.properties配置文件中的kafka配置。
3）生成bean，@Bean
package com.kangaroo.sentinel.collect.configuration;
import java.util.HashMap;
import java.util.Map;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.serialization.StringSerializer;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.annotation.EnableKafka;
import org.springframework.kafka.core.DefaultKafkaProducerFactory;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.core.ProducerFactory;
@Configuration
@EnableKafka
public class KafkaProducerConfig {
@Value("${kafka.producer.servers}")
private String servers;
@Value("${kafka.producer.retries}")
private int retries;
@Value("${kafka.producer.batch.size}")
private int batchSize;
@Value("${kafka.producer.linger}")
private int linger;
@Value("${kafka.producer.buffer.memory}")
private int bufferMemory;
public Map producerConfigs() {
Map props = new HashMap<>();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, servers);
props.put(ProducerConfig.RETRIES_CONFIG, retries);
props.put(ProducerConfig.BATCH_SIZE_CONFIG, batchSize);
props.put(ProducerConfig.LINGER_MS_CONFIG, linger);
props.put(ProducerConfig.BUFFER_MEMORY_CONFIG, bufferMemory);
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
return props;
}
public ProducerFactory producerFactory() {
return new DefaultKafkaProducerFactory<>(producerConfigs());
}
@Bean
public KafkaTemplate kafkaTemplate() {
return new KafkaTemplate(producerFactory());
}
}
实验我们的producer，写一个Controller。想topic=test，key=key，发送消息message
package com.kangaroo.sentinel.collect.controller;
import com.kangaroo.sentinel.common.response.Response;
import com.kangaroo.sentinel.common.response.ResultCode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.web.bind.annotation.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@RestController
@RequestMapping("/kafka")
public class CollectController {
protected final Logger logger = LoggerFactory.getLogger(this.getClass());
@Autowired
private KafkaTemplate kafkaTemplate;
@RequestMapping(value = "/send", method = RequestMethod.GET)
public Response sendKafka(HttpServletRequest request, HttpServletResponse response) {
try {
String message = request.getParameter("message");
logger.info("kafka的消息={}"， message);
kafkaTemplate.send("test", "key", message);
logger.info("发送kafka成功.");
return new Response(ResultCode.SUCCESS, "发送kafka成功", null);
} catch (Exception e) {
logger.error("发送kafka失败", e);
return new Response(ResultCode.EXCEPTION, "发送kafka失败", null);
}
}
}
3、configuration：kafka consumer
1）通过@Configuration、@EnableKafka，声明Config并且打开KafkaTemplate能力。
2）通过@Value注入application.properties配置文件中的kafka配置。
3）生成bean，@Bean
package com.kangaroo.sentinel.collect.configuration;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.annotation.EnableKafka;
import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
import org.springframework.kafka.config.KafkaListenerContainerFactory;
import org.springframework.kafka.core.ConsumerFactory;
import org.springframework.kafka.core.DefaultKafkaConsumerFactory;
import org.springframework.kafka.listener.ConcurrentMessageListenerContainer;
import java.util.HashMap;
import java.util.Map;
@Configuration
@EnableKafka
public class KafkaConsumerConfig {
@Value("${kafka.consumer.servers}")
private String servers;
@Value("${kafka.consumer.enable.auto.commit}")
private boolean enableAutoCommit;
@Value("${kafka.consumer.session.timeout}")
private String sessionTimeout;
@Value("${kafka.consumer.auto.commit.interval}")
private String autoCommitInterval;
@Value("${kafka.consumer.group.id}")
private String groupId;
@Value("${kafka.consumer.auto.offset.reset}")
private String autoOffsetReset;
@Value("${kafka.consumer.concurrency}")
private int concurrency;
@Bean
public KafkaListenerContainerFactory> kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory factory = new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory());
factory.setConcurrency(concurrency);
factory.getContainerProperties().setPollTimeout(1500);
return factory;
}
public ConsumerFactory consumerFactory() {
return new DefaultKafkaConsumerFactory<>(consumerConfigs());
}
public Map consumerConfigs() {
Map propsMap = new HashMap<>();
propsMap.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, servers);
propsMap.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, enableAutoCommit);
propsMap.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, autoCommitInterval);
propsMap.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, sessionTimeout);
propsMap.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
propsMap.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
propsMap.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
propsMap.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, autoOffsetReset);
return propsMap;
}
@Bean
public Listener listener() {
return new Listener();
}
}
new Listener()生成一个bean用来处理从kafka读取的数据。Listener简单的实现demo如下：只是简单的读取并打印key和message值
@KafkaListener中topics属性用于指定kafka topic名称，topic名称由消息生产者指定，也就是由kafkaTemplate在发送消息时指定。
package com.kangaroo.sentinel.collect.configuration;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.kafka.annotation.KafkaListener;
public class Listener {
protected final Logger logger = LoggerFactory.getLogger(this.getClass());
@KafkaListener(topics = {"test"})
public void listen(ConsumerRecord record) {
logger.info("kafka的key: " + record.key());
logger.info("kafka的value: " + record.value().toString());
}
}
tips:
1）我没有介绍如何安装配置kafka，配置kafka时最好用完全bind网络ip的方式，而不是localhost或者127.0.0.1
2）最好不要使用kafka自带的zookeeper部署kafka，可能导致访问不通。
3）理论上consumer读取kafka应该是通过zookeeper，但是这里我们用的是kafkaserver的地址，为什么没有深究。
4）定义监听消息配置时，GROUP_ID_CONFIG配置项的值用于指定消费者组的名称，如果同组中存在多个监听器对象则只有一个监听器对象能收到消息。