Spring Boot Kafka 入门示例
Spring Boot 的便捷,无出其右,仍然是三部曲,创建springboot 项目,配置项目,编写示例代码。
安装 Kafka 测试环境请参加: https://blog.csdn.net/fishpro/article/details/105761986
本示例代码https://github.com/fishpro/spring-boot-study/tree/master/spring-boot-study-kafka
1 新建 Spring Boot Maven 示例工程项目
注意:是用来 IDEA 开发工具
File > New > Project
,如下图选择Spring Initializr
然后点击 【Next】下一步- 填写
GroupId
(包名)、Artifact
(项目名) 即可。点击 下一步
groupId=com.fishpro
artifactId=kafka - 选择依赖
Spring Web Starter
前面打钩。 - 项目名设置为
spring-boot-study-kafka
.
2 引入依赖 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>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.fishpro</groupId>
<artifactId>kafka</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>kafka</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>public</id>
<name>aliyun nexus</name>
<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
<releases>
<enabled>true</enabled>
</releases>
</repository>
</repositories>
</project>
3 application 配置
spring:
kafka:
# 指定kafka server的地址,集群配多个,中间,逗号隔开
bootstrap-servers: 127.0.0.1:9092
# 生产者
producer:
# 写入失败时,重试次数。当leader节点失效,一个repli节点会替代成为leader节点,此时可能出现写入失败,
# 当retris为0时,produce不会重复。retirs重发,此时repli节点完全成为leader节点,不会产生消息丢失。
retries: 0
# 每次批量发送消息的数量,produce积累到一定数据,一次发送
batch-size: 16384
# produce积累数据一次发送,缓存大小达到buffer.memory就发送数据
buffer-memory: 33554432
# 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
properties:
linger.ms: 1
# 消费者
consumer:
enable-auto-commit: false
auto-commit-interval: 100ms
key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
properties:
session.timeout.ms: 15000
group-id: group
server:
port: 8081
4 代码实例
4.1 发送消息
建立文件 KafkaDemoController.java 设置为 RestController
package com.fishpro.kafka.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class KafkaDemoController {
@Autowired
private KafkaTemplate<String,Object> kafkaTemplate;
@GetMapping("/message/send")
public boolean send(@RequestParam String message){
kafkaTemplate.send("testTopic",message);
return true;
}
}
4.2 接收消息
新建文件 CustomerListener 设置标签为 @Component
package com.fishpro.kafka.listener;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;
@Component
public class CustomerListener {
@KafkaListener(topics="testTopic")
public void onMessage(String message){
System.out.println(message);
}
}
4.3 测试发送与接收
输入发送消息 url http://localhost:8081/message/send?message=abc
此时 CustomerListener 也会实时接收到消息。
4.4 问题
- 出现了:springboot整合kafka出现No group.id found in consumer config
- 原因是 未配置消费端
# 消费者
consumer:
enable-auto-commit: false
auto-commit-interval: 100ms
key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
properties:
session.timeout.ms: 15000
group-id: group
4.5 异步同步消息
建立异步消息同步消息发送
package com.fishpro.kafka.service;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.support.SendResult;
import org.springframework.stereotype.Service;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.ListenableFutureCallback;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
@Service
public class KafkaSendService {
@Autowired
private KafkaTemplate<String,Object> kafkaTemplate;
/**
* 异步示例
* */
public void sendAnsyc(final String topic,final String message){
ListenableFuture<SendResult<String, Object>> future = kafkaTemplate.send(topic,message);
future.addCallback(new ListenableFutureCallback<SendResult<String, Object>>() {
@Override
public void onSuccess(SendResult<String, Object> result) {
System.out.println("发送消息成功:" + result);
}
@Override
public void onFailure(Throwable ex) {
System.out.println("发送消息失败:"+ ex.getMessage());
}
});
}
/**
* 同步示例
* */
public void sendSync(final String topic,final String message){
ProducerRecord<String, Object> producerRecord = new ProducerRecord<>(topic, message);
try {
kafkaTemplate.send(producerRecord).get(10, TimeUnit.SECONDS);
System.out.println("发送成功");
}
catch (ExecutionException e) {
System.out.println("发送消息失败:"+ e.getMessage());
}
catch (TimeoutException | InterruptedException e) {
System.out.println("发送消息失败:"+ e.getMessage());
}
}
}
修改 KafkaDemoController 增加异步同步消息测试
/**
* kafka 消息发送
* */
@RestController
public class KafkaDemoController {
@Autowired
private KafkaTemplate<String,Object> kafkaTemplate;
@Autowired
private KafkaSendService kafkaSendService;
@GetMapping("/message/send")
public boolean send(@RequestParam String message){
kafkaTemplate.send("testTopic",message);
return true;
}
//同步
@GetMapping("/message/sendSync")
public boolean sendSync(@RequestParam String message){
kafkaSendService.sendSync("synctopic",message);
return true;
}
//异步示例
@GetMapping("/message/sendAnsyc")
public boolean sendAnsys(@RequestParam String message){
kafkaSendService.sendAnsyc("ansyctopic",message);
return true;
}
//事务消息发送
// @GetMapping("/message/sendTransaction")
// public boolean sendTransaction(){
// kafkaTemplate.executeInTransaction(kafkaTemplate -> {
// kafkaTemplate.send("transactionTopic", "TransactionMessage");
// return true;
// });
// return true;
// }
}
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