场景描述：上文写到，不断接收数据并存放到OSS，现在要把数据存到MQ的kafka一份。

springboot版本为1.5.9。

开工之前先阅读阿里云官方kafka消息接入说明：https://help.aliyun.com/document_detail/52376.html

1、首先引入kafka jar包

spring-kafka目前最新版本为2.1.2，其依赖的kafka-clients是1.0.x，但Kafka 服务端版本是 0.10，Client 版本建议 0.10，所以此处需排除依赖重新引入，否则一直报错：

Bootstrap broker kafka-ons-internet.aliyun.com:8080 disconnected

2、KafkaConfiguration.java

@Configuration
@EnableKafka
public class KafkaConfiguration {

	@Value("${kafka.broker.address}")
	private String brokerAddress;

	@Value("${kafka.default.topic}")
	private String defaultTopic;

	@Value("${kafka.jks.location}")
	private String jksLocation;

	public KafkaConfiguration() {
		URL authLocation = KafkaConfiguration.class.getClassLoader().getResource("kafka_client_jaas.conf");
		if (System.getProperty("java.security.auth.login.config") == null) {
			System.setProperty("java.security.auth.login.config", authLocation.toExternalForm());
		}
	}

	public Map<String, Object> producerConfigs() {
		Map<String, Object> props = new HashMap<String, Object>();
		props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, brokerAddress);
		if (StringUtils.isEmpty(jksLocation)) {
			props.put(SslConfigs.SSL_TRUSTSTORE_LOCATION_CONFIG, KafkaConfiguration.class.getClassLoader().getResource("kafka.client.truststore.jks").getPath());
		} else {
			props.put(SslConfigs.SSL_TRUSTSTORE_LOCATION_CONFIG, jksLocation);
		}
		props.put(SslConfigs.SSL_TRUSTSTORE_PASSWORD_CONFIG, "KafkaOnsClient");
		props.put(CommonClientConfigs.SECURITY_PROTOCOL_CONFIG, "SASL_SSL");
		props.put(SaslConfigs.SASL_MECHANISM, "ONS");
		props.put(ProducerConfig.RETRIES_CONFIG, 0);
		props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
		props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
		props.put(ProducerConfig.MAX_BLOCK_MS_CONFIG, 30 * 1000);
		return props;
	}

	public ProducerFactory<String, String> producerFactory() {
		return new DefaultKafkaProducerFactory<String, String>(producerConfigs());
	}

	@Bean
	public KafkaTemplate<String, String> kafkaTemplate() {
		KafkaTemplate kafkaTemplate = new KafkaTemplate<String, String>(producerFactory());
		kafkaTemplate.setDefaultTopic(defaultTopic);
		return kafkaTemplate;
	}
}

注意此处定义了三个变量，通过配置文件注入：

brokerAddress kafka服务器地址

defaultTopic kafka默认topic

jksLocation JKS文件地址（开发环境无需定义，直接读取resources下的jks，但生产环境需读取jar包外部的jks文件，所以此处需配置路径）

3、将《kafka消息接入说明》中的kafka_client_jaas.conf和根证书kafka.client.truststore.jks放到resources/目录下

4、KafkaService.java

@Component
public class KafkaService {

	@Autowired
	private KafkaTemplate<String, String> kafkaTemplate;

	public void send(ProbeData probeData) {
		String deviceMac = probeData.getDev_mac();
		String shopId = probeData.getShopId();
		List<UserData> data = probeData.getData();

		StringBuilder msgSB = new StringBuilder();
		if (data != null && !data.isEmpty()) {
			for (UserData userData : data) {
				String visitorMac = userData.getUsr_mac();
				String visitorTime = userData.getUsr_cap_time();
				String msg = shopId + "," + deviceMac + "," + visitorMac + "," + visitorTime;

				msgSB.append(msg).append(";");
			}
			ListenableFuture futher = kafkaTemplate.sendDefault(msgSB.toString());
			/*
				// 此处用于控制是否同步
				try {
					futher.get();
				} catch (InterruptedException e) {
					e.printStackTrace();
				} catch (ExecutionException e) {
					e.printStackTrace();
				}
			*/
		}
	}
}

关键代码就一句：

kafkaTemplate.sendDefault(msgSB.toString());

此处为异步发送，一开始用测试类测试时总是写入不了kafka，后来发现是因为公网异步写入太慢，而测试类执行完后退出，导致异步中断。

测试时可以改为同步发送，即：

ListenableFuture futher = kafkaTemplate.sendDefault(msgSB.toString());
futher.get();