springboot集成kafka

创建工程

• 父工程pom

父工程做了子工程管理和包管理

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.15</version>
    </parent>

    <groupId>com.wzw</groupId>
    <artifactId>kafka</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <packaging>pom</packaging>

    <modules>
        <module>producer</module>
    </modules>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
                <version>2.4.13</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.kafka</groupId>
                <artifactId>spring-kafka</artifactId>
                <version>2.8.1</version>
            </dependency>
        </dependencies>
    </dependencyManagement>


</project>

发布者

• pom
  引入包，继承父工程

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>com.wzw</groupId>
        <artifactId>kafka</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <groupId>com.wzw</groupId>
    <artifactId>producer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>producer</name>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka</artifactId>
        </dependency>
    </dependencies>


</project>

• yml

server:
  port: 7070
spring:
  kafka:
    bootstrap-servers: 192.168.3.32:19092
    producer: # 生产者
      retries: 3 # 设置大于 0 的值，则客户端会将发送失败的记录重新发送
      batch-size: 16384
      buffer-memory: 33554432
      acks: 1
      # 指定消息key和消息体的编解码方式
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
    consumer:
      group-id: default-group
      enable-auto-commit: false
      auto-offset-reset: earliest
      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      max-poll-records: 500
    listener:
      # 当每一条记录被消费者监听器（ListenerConsumer）处理之后提交
      # RECORD
      # 当每一批poll()的数据被消费者监听器（ListenerConsumer）处理之后提交
      # BATCH
      # 当每一批poll()的数据被消费者监听器（ListenerConsumer）处理之后，距离上次提交时间大于TIME时提交
      # TIME
      # 当每一批poll()的数据被消费者监听器（ListenerConsumer）处理之后，被处理record数量大于等于COUNT时提交
      # COUNT
      # TIME | COUNT　有一个条件满足时提交
      # COUNT_TIME
      # 当每一批poll()的数据被消费者监听器（ListenerConsumer）处理之后, 手动调用Acknowledgment.acknowledge()后提交
      # MANUAL
      # 手动调用Acknowledgment.acknowledge()后立即提交，一般使用这种
      # MANUAL_IMMEDIATE
      ack-mode: MANUAL_IMMEDIATE

• config配置类

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.core.DefaultKafkaProducerFactory;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.core.ProducerFactory;

import java.util.HashMap;
import java.util.Map;

@Configuration
public class KafkaProducerConfig {

    @Value("${spring.kafka.bootstrap-servers}")
    private String bootstrapServers;

    @Bean
    public Map<String, Object> producerConfigs() {
        Map<String, Object> props = new HashMap<>();
        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        return props;
    }

    @Bean
    public ProducerFactory<String, String> producerFactory() {
        return new DefaultKafkaProducerFactory<>(producerConfigs());
    }

    @Bean
    public KafkaTemplate<String, String> kafkaTemplate() {
        return new KafkaTemplate<>(producerFactory());
    }

}

• 请求测试接口

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class KafkaController {

    @Autowired
    private KafkaTemplate<String, String> kafkaTemplate;

    @RequestMapping("/send")
    public void sendMessage(String message) {
        kafkaTemplate.send("my-topic", message);
    }

}

订阅者

• pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.wzw</groupId>
        <artifactId>kafka</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <groupId>com.example</groupId>
    <artifactId>consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>consumer</name>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka</artifactId>
        </dependency>
    </dependencies>

</project>

• yml

server:
  port: 7071
spring:
  kafka:
    bootstrap-servers: 192.168.3.32:19092
    producer: # 生产者
      retries: 3 # 设置大于 0 的值，则客户端会将发送失败的记录重新发送
      batch-size: 16384
      buffer-memory: 33554432
      acks: 1
      # 指定消息key和消息体的编解码方式
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
    consumer:
      group-id: default-group
      enable-auto-commit: false
      auto-offset-reset: earliest
      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      max-poll-records: 500
    listener:
      # 当每一条记录被消费者监听器（ListenerConsumer）处理之后提交
      # RECORD
      # 当每一批poll()的数据被消费者监听器（ListenerConsumer）处理之后提交
      # BATCH
      # 当每一批poll()的数据被消费者监听器（ListenerConsumer）处理之后，距离上次提交时间大于TIME时提交
      # TIME
      # 当每一批poll()的数据被消费者监听器（ListenerConsumer）处理之后，被处理record数量大于等于COUNT时提交
      # COUNT
      # TIME | COUNT　有一个条件满足时提交
      # COUNT_TIME
      # 当每一批poll()的数据被消费者监听器（ListenerConsumer）处理之后, 手动调用Acknowledgment.acknowledge()后提交
      # MANUAL
      # 手动调用Acknowledgment.acknowledge()后立即提交，一般使用这种
      # MANUAL_IMMEDIATE
      ack-mode: MANUAL_IMMEDIATE

• 配置类

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.core.ConsumerFactory;
import org.springframework.kafka.core.DefaultKafkaConsumerFactory;

import java.util.HashMap;
import java.util.Map;

@Configuration
@EnableKafka
public class KafkaConsumerConfig {

    @Value("${spring.kafka.bootstrap-servers}")
    private String bootstrapServers;

    @Value("${spring.kafka.consumer.group-id}")
    private String groupId;

    @Bean
    public Map<String, Object> consumerConfigs() {
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        return props;
    }

    @Bean
    public ConsumerFactory<String, String> consumerFactory() {
        return new DefaultKafkaConsumerFactory<>(consumerConfigs());
    }

    @Bean
    public ConcurrentKafkaListenerContainerFactory<String, String> kafkaListenerContainerFactory() {
        ConcurrentKafkaListenerContainerFactory<String, String> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(consumerFactory());
        return factory;
    }

}

• 监听类
  有消息进来就输出

import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Service;

@Service
public class KafkaConsumer {

    @KafkaListener(topics = "my-topic", groupId = "default-group")
    public void consume(String message) {
        System.out.println("Received message: " + message);
    }

}

测试

注意事项

kafka的配置文件kafka_2.13-2.8.1/config/server.properties，里面有三个配置需要注意，不然的话服务器测试正常，但是java或者其它地址的客户端报错

我的环境是docker搭建的，

• listeners
  kafka容器的网络地址是172.18.0.5，kafka的端口是9092
  listeners=PLAINTEXT://172.18.0.5:9092
  我的虚拟机ip是192.168.3.32，然后启动kafka容器的时候，映射的地址是-p 19092:9092
  不配置正确的话，会连接不到，可能报错Connection to node 1 (kafka1/172.18.0.2:9092) could not be established. Broker may not be available.
• advertised.listeners
  advertised.listeners=PLAINTEXT://192.168.3.32:39092
  不配置正确的话，会连接不到，可能报错kafka disconnecting from node xxx due to request timeout.
• advertised.host.name
  最底下有个属性advertised.host.name
  配置成kafka容器的网络地址172.18.0.5
  advertised.host.name=172.18.0.5
  如果这里不配置advertised.host.name为ip，而是使用名称，会报错，

  配置为：advertised.host.name=kafka
  报错如下
  Error connecting to node kafka:19092 (id: 1001 rack: null)
  

  解决方法：访问的客户端需要修改hosts，太麻烦，所以直接修改成ip