java - 找不到 key.serializer 的类

Question

我使用 Spring boot 应用程序将 JSON 数据数组发送到 Kafka 主题，但出现以下错误:

error :org.apache.kafka.common.config.ConfigException: Invalid value 
org.apache.kafka.common.serialization.StringSerializer; for 
configuration key.serializer: Class 
org.apache.kafka.common.serialization.StringSerializer; could not be found.

我尝试将序列化配置更改为:

props.put("key.serializer",  org.apache.kafka.common.serialization.StringSerializer;");
props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer;");

至

props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer;");
props.put("value.serializer", "org.apache.kafka.common.serialization.ByteArraySerializer;");

配置文件和服务文件代码:

@Configuration
public class KafkaProducerConfig {

@Bean

private static ProducerFactory<String, String> producerConfig() {

            Properties props = new Properties();
            props.put("bootstrap.servers", "localhost:9092");
            props.put("acks", "all");
            props.put("retries", 0);
            props.put("batch.size", 16384);
            props.put("linger.ms", 1);
            props.put("buffer.memory", 33554432);
            props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer;");
            props.put("value.serializer", "org.apache.kafka.common.serialization.ByteArraySerializer;");

            // The following properties are used by LiKafkaProducerImpl
            props.put("large.message.enabled", "true");
            props.put("max.message.segment.bytes", 1000 * 1024);
            props.put("segment.serializer", DefaultSegmentSerializer.class.getName());

            props.put("auditor.class", LoggingAuditor.class.getName());

            return new DefaultKafkaProducerFactory(props);
        }
}

@Service
public class KafkaSender {

    private static final Logger LOGGER = LoggerFactory.getLogger(KafkaSender.class);

    @Autowired
    private KafkaTemplate<String, String> kafkaTemplate;

    @Value("${kafka.topic.name}")
    private String topicName;

    public void sendData(List<Student> student) {

        System.out.println("Inside Student"+ student.toString());
        System.out.println("Inside Student"+ student);

        // TODO Auto-generated method stub
        Map<String, Object> headers = new HashMap<>();
        headers.put(KafkaHeaders.TOPIC, topicName);     

        System.out.println("\nStudent=  " + headers);

        // Construct a JSONObject from a Map.
        JSONObject HeaderObject = new JSONObject(headers);
        System.out.println("\nUsing new JSONObject() ==> " + HeaderObject);
        final String record = HeaderObject.toString();

        final int recordSize = record.length();

        kafkaTemplate.send(new GenericMessage<>(student, headers));

        LOGGER.info("Data - " + student + " sent to Kafka Topic - " + topicName);
    }
}

POST json:

[{ "学生号": "Q45678123", “名字”:“abc”， “姓氏”:“xyz”， “年龄”:“12”， “地址”: { “公寓”:“123号公寓”， "street": "街道信息", “状态”:“状态”， “城市”:“城市”， “邮政编码”:“12345” } }, { "学生号": "Q45678123", “名字”:“abc”， “姓氏”:“xyz”， “年龄”:“12”， “地址”: { “公寓”:“123号公寓”， "street": "街道信息", “状态”:“状态”， “城市”:“城市”， “邮政编码”:“12345” } } ]

Answer 1

您需要删除值末尾的分号

props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
props.put("value.serializer", "org.apache.kafka.common.serialization.ByteArraySerializer");

或者您可以使用 class.getName() 方法，就像您对段序列化器所做的那样，我建议这种方法更安全，因为这样可以保证您想要的序列化器在编译时可用