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编程小技巧。

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