SpringBoot -- Kafka(二) Demo

前置工作

• Kafka 、zookeeper环境已经完成
• JDK完成安装（kafka环境依赖jvm）
• 了解kafka、zookeeper各种的作用

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Demo

• 依然使用现有的feignserver
• 有说Springboot 1.5+ 已经支持spring-integration 无缝对接
• 本文依然使用的 1.4+，所以还是采用config方式

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引入kafka依赖

build.gradle

compile ('org.springframework.integration:spring-integration-core:4.3.6.RELEASE')compile ('org.springframework.kafka:spring-kafka:1.1.0.RELEASE')

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配置参数：broker、zk、group等
application.yml

bootcwenao:  kafka:    binder:      brokers: localhost:9092      zk-nodes: localhost:2181    group: cwenao-group

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创建KafkaProducersConfig并使用@Configuration、@EnableKafka

/** * @author cwenao * @version $Id KafkaConfig.java, v 0.1 2017-01-20 9:51 cwenao Exp $$ */@Configuration@EnableKafkapublic class KafkaProducersConfig {    @Value("${bootcwenao.kafka.binder.brokers}")    private String brokers;    @Bean("kafkaTemplate")    public KafkaTemplate<String, String> kafkaTemplate() {        KafkaTemplate<String, String> kafkaTemplate = new KafkaTemplate<String, String>(producerFactory());        return kafkaTemplate;    }    public ProducerFactory<String, String> producerFactory() {        // set the producer properties        Map<String, Object> properties = new HashMap<String, Object>();        properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, brokers);        properties.put(ProducerConfig.RECEIVE_CONFIG, 0);        properties.put(ProducerConfig.BATCH_SIZE_CONFIG, 4096);        properties.put(ProducerConfig.LINGER_MS_CONFIG, 1);        properties.put(ProducerConfig.BUFFER_MEMORY_CONFIG, 40960);        properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);        properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);        return new DefaultKafkaProducerFactory<String, String>(properties);    }}

创建Listener 处理消息，使用@KafkaListener，用户监听topic

/** * @author cwenao * @version $Id KafkaListeners.java, v 0.1 2017-01-21 21:31 cwenao Exp $$ */public class KafkaListeners {    @KafkaListener(topics = {"bootcwenaoTopic"})    public void testListener(ConsumerRecord<?, ?> record) {        Optional<?> messages = Optional.ofNullable(record.value());        if (messages.isPresent()) {            Object msg = messages.get();            System.out.println("  this is the testTopic send message: " + msg);        }    }}

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创建KafkaConsumerConfig并使用@Configuration、@EnableKafka

/** * @author cwenao * @version $Id KafkaConsumerConfig.java, v 0.1 2017-01-21 21:11 cwenao Exp $$ */@Configuration@EnableKafkapublic class KafkaConsumerConfig {    @Value("${bootcwenao.kafka.binder.brokers}")    private String brokers;    @Value("${bootcwenao.kafka.group}")    private String group;    @Bean    public KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<String, String>> kafkaListenerContainerFactory() {        ConcurrentKafkaListenerContainerFactory<String, String> factory = new ConcurrentKafkaListenerContainerFactory<String, String>();        factory.setConsumerFactory(consumerFactory());        factory.setConcurrency(4);        factory.getContainerProperties().setPollTimeout(4000);        return factory;    }    @Bean    public KafkaListeners kafkaListeners() {        return new KafkaListeners();    }    public ConsumerFactory<String, String> consumerFactory() {        Map<String, Object> properties = new HashMap<String, Object>();        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, brokers);        properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, false);        properties.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, "100");        properties.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, "15000");        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);        properties.put(ConsumerConfig.GROUP_ID_CONFIG, group);        properties.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "latest");        return new DefaultKafkaConsumerFactory<String, String>(properties);    }}

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测试

创建生产者发送信息方法testKafka

/** * @author cwenao * @version $Id FeignController.java, v 0.1 2017-01-15 13:50 cwenao Exp $$ */@Controllerpublic class FeignController {    @Autowired    KafkaTemplate kafkaTemplate;    @RequestMapping("/testKafka")    @ResponseBody    public void testkafka(String message) {        kafkaTemplate.send("bootcwenaoTopic", "bootcwnao", message);    }}

依次启动 discovery、configserver、 apigateway、feignserver

浏览器中输入 http://localhost:10002/servers/testKafka?message=aaaaaaaaaaabbbbb

可以看到KafkaListeners中输出 this is the testTopic send message: aaaaaaaaaaabbbbb

可能的错误

• kafka版本不对，现在这种方式只能支持0.10.x.x
• kafka配置没有对外开放host、port
  

• advertised.host.name、advertised.port
• broker-list配置的不对

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代码

代码请移步 Github参考地址

如有疑问请加公众号（K171），如果觉得对您有帮助请 github start