Springboot集成kafka

一.kafka在mac环境下的安装

1.安装kafka

$brew install kafka

上面安装过程中已经自动安装了zookeeper

2.软件位置

/usr/local/Cellar/zookeeper
/usr/local/Cellar/kafka

3.配置文件位置

/usr/local/etc/kafka/zookeeper.properties
/usr/local/etc/kafka/server.properties

备注：后续操作均需进入 /usr/local/Cellar/kafka/1.0.0/bin 目录下。

4.启动zookeeper

zookeeper-server-start /usr/local/etc/kafka/zookeeper.properties &

5.启动kafka服务

kafka-server-start /usr/local/etc/kafka/server.properties &

6.创建topic

kafka-topics --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic test1

7.查看创建的topic

kafka-topics --list --zookeeper localhost:2181  

8.生产数据

kafka-console-producer --broker-list localhost:9092 --topic test1

9.消费数据

kafka-console-consumer --bootstrap-server 127.0.0.1:9092 --topic test1 --from-beginning

备注：–from-beginning 将从第一个消息开始接收

二.springboot集成kafka

1.pom文件依赖

<?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>2.1.3.RELEASE</version>
		<relativePath/>
	</parent>
	<groupId>com.ligh</groupId>
	<artifactId>Springboot-kafka</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>Springboot-kafka</name>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.kafka</groupId>
			<artifactId>spring-kafka</artifactId>
		</dependency>
		<dependency>
			<groupId>com.google.code.gson</groupId>
			<artifactId>gson</artifactId>
			<version>2.8.2</version>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
</project>

2.在配置文件application.properties中添加以下配置

#============== kafka ===================
# 指定kafka 代理地址，可以多个
spring.kafka.bootstrap-servers=127.0.0.1:9092

#=============== provider  =======================
spring.kafka.producer.retries=0
# 每次批量发送消息的数量
spring.kafka.producer.batch-size=16384
spring.kafka.producer.buffer-memory=33554432

# 指定消息key和消息体的编解码方式
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.apache.kafka.common.serialization.StringSerializer

#=============== consumer  =======================
# 指定默认消费者group id
spring.kafka.consumer.group-id=test-consumer-group

spring.kafka.consumer.auto-offset-reset=earliest
spring.kafka.consumer.enable-auto-commit=true
spring.kafka.consumer.auto-commit-interval=100

# 指定消息key和消息体的编解码方式
spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.consumer.value-deserializer=org.apache.kafka.common.serialization.StringDeserializer

3.创建一个实体类Message

import lombok.Data;
import java.util.Date;
@Data
public class Message {

    private Long id;     //id

    private String msg;  //消息

    private Date sendTime; //时间戳
    
}

4.创建生产者端

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.ligh.domain.Message;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.util.Date;
import java.util.UUID;
@Component
@Slf4j
@Controller
public class KafkaProducer {

    @Autowired
    private KafkaTemplate<String,String> kafkaTemplate;
    private Gson gson = new GsonBuilder().create();

    //发送消息
    @RequestMapping("send")
    @ResponseBody
    public String send(){
        Message message = new Message();
        message.setId(System.currentTimeMillis());
        message.setMsg(UUID.randomUUID().toString());
        message.setSendTime(new Date());
        System.out.println("+++++++++++  message = {}" +(gson.toJson(message)));
        kafkaTemplate.send("ligh",gson.toJson(message));
        return "success";
    }
}

5.创建消费者端

import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;
import java.util.Optional;

@Component
@Slf4j
public class KafkaConsumer {
    @KafkaListener(topics = {"ligh"})
    public void listen(ConsumerRecord<?,?> record){
        Optional<?> kafkaMessage = Optional.ofNullable(record.value());
        if(kafkaMessage.isPresent()){
            Object message = kafkaMessage.get();
            System.out.println("--------- recode = "+record);
            System.out.println("--------- message = "+message);
        }
    }
}

三.测试

1.访问localhost:8080/send进行生产者生产消息

2.查看控制台消费者是否消费到了消息

以上就完成了kafka的安装到集成到springboot中的过程。