Spring Boot集成Kafka的示例代码

本文介绍了Spring Boot集成Kafka的示例代码，分享给大家，也给自己留个笔记

系统环境

使用远程服务器上搭建的kafka服务

1. Ubuntu 16.04 LTS
2. kafka_2.12-0.11.0.0.tgz
3. zookeeper-3.5.2-alpha.tar.gz

集成过程

1.创建spring boot工程，添加相关依赖：

<?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>
<groupId>com.laravelshao.springboot</groupId>
<artifactId>spring-boot-integration-kafka</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>spring-boot-integration-kafka</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<!--kafka-->
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-json</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

2.添加配置信息，这里使用yml文件

spring:
kafka:
bootstrap-servers:X.X.X.X:9092
producer:
value-serializer: org.springframework.kafka.support.serializer.JsonSerializer
consumer:
group-id: test
auto-offset-reset: earliest
value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
properties:
spring:
json:
trusted:
packages: com.laravelshao.springboot.kafka

3.创建消息对象

public class Message {
private Integer id;
private String msg;
public Message() {
}
public Message(Integer id, String msg) {
this.id = id;
this.msg = msg;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
@Override
public String toString() {
return "Message{" +
"id=" + id +
", msg='" + msg + '\'' +
'}';
}
}

4.创建生产者

package com.laravelshao.springboot.kafka;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.stereotype.Component;
/**
* Created by shaoqinghua on 2018/3/23.
*/
@Component
public class Producer {
private static Logger log = LoggerFactory.getLogger(Producer.class);
@Autowired
private KafkaTemplate kafkaTemplate;
public void send(String topic, Message message) {
kafkaTemplate.send(topic, message);
log.info("Producer->topic:{}, message:{}", topic, message);
}
}

5.创建消费者，使用@ KafkaListener注解监听主题

package com.laravelshao.springboot.kafka;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;
/**
* Created by shaoqinghua on 2018/3/23.
*/
@Component
public class Consumer {
private static Logger log = LoggerFactory.getLogger(Consumer.class);
@KafkaListener(topics = "test_topic")
public void receive(ConsumerRecord<String, Message> consumerRecord) {
log.info("Consumer->topic:{}, value:{}", consumerRecord.topic(), consumerRecord.value());
}
}

6.发送消费测试

package com.laravelshao.springboot;
import com.laravelshao.springboot.kafka.Message;
import com.laravelshao.springboot.kafka.Producer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
@SpringBootApplication
public class IntegrationKafkaApplication {
public static void main(String[] args) throws InterruptedException {
ApplicationContext context = SpringApplication.run(IntegrationKafkaApplication.class, args);
Producer producer = context.getBean(Producer.class);
for (int i = 1; i < 10; i++) {
producer.send("test_topic", new Message(i, "test topic message " + i));
Thread.sleep(2000);
}
}
}

可以依次看到发送消息，消费消息

异常问题

反序列化异常(自定义的消息对象不在kafka信任的包路径下)？

[org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1] ERROR org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.719 Container exception
org.apache.kafka.common.errors.SerializationException: Error deserializing key/value for partition test_topic-0 at offset 9. If needed, please seek past the record to continue consumption.
Caused by: java.lang.IllegalArgumentException: The class 'com.laravelshao.springboot.kafka.Message' is not in the trusted packages: [java.util, java.lang]. If you believe this class is safe to deserialize, please provide its name. If the serialization is only done by a trusted source, you can also enable trust all (*).
 at org.springframework.kafka.support.converter.DefaultJackson2JavaTypeMapper.getClassIdType(DefaultJackson2JavaTypeMapper.java:139)
 at org.springframework.kafka.support.converter.DefaultJackson2JavaTypeMapper.toJavaType(DefaultJackson2JavaTypeMapper.java:113)
 at org.springframework.kafka.support.serializer.JsonDeserializer.deserialize(JsonDeserializer.java:191)
 at org.apache.kafka.clients.consumer.internals.Fetcher.parseRecord(Fetcher.java:923)
 at org.apache.kafka.clients.consumer.internals.Fetcher.access$2600(Fetcher.java:93)
 at org.apache.kafka.clients.consumer.internals.Fetcher$PartitionRecords.fetchRecords(Fetcher.java:1100)
 at org.apache.kafka.clients.consumer.internals.Fetcher$PartitionRecords.access$1200(Fetcher.java:949)
 at org.apache.kafka.clients.consumer.internals.Fetcher.fetchRecords(Fetcher.java:570)
 at org.apache.kafka.clients.consumer.internals.Fetcher.fetchedRecords(Fetcher.java:531)
 at org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:1146)
 at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1103)
 at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.run(KafkaMessageListenerContainer.java:667)
 at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
 at java.util.concurrent.FutureTask.run(FutureTask.java:266)
 at java.lang.Thread.run(Thread.java:745)

解决方法：将当前包添加到kafka信任的包路径下

spring:
kafka:
consumer:
properties:
spring:
json:
trusted:
packages: com.laravelshao.springboot.kafka

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。

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