本文介绍了KafkaException:类不是org.apache.kafka.common.serialization.Deserializer的实例的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想实现发送和接收Java序列化对象的Kafka生产者.我试过了:
I want to implement Kafka producer which sends and receives Java Serialized Objects. I tried this:
制作人:
@Configuration
public class KafkaProducerConfig {
@Value(value = "${kafka.bootstrapAddress}")
private String bootstrapAddress;
@Bean
public ProducerFactory<String, SaleRequestFactory> saleRequestFactoryProducerFactory() {
Map<String, Object> configProps = new HashMap<>();
configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
configProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, SaleRequestFactory.class);
configProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, SaleRequestFactory.class);
return new DefaultKafkaProducerFactory<>(configProps);
}
@Bean
public ProducerFactory<String, String> producerFactory() {
Map<String, Object> configProps = new HashMap<>();
configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
/*
Serialization configuration
*/
return new DefaultKafkaProducerFactory<>(configProps);
}
@Bean
public KafkaTemplate<String, SaleRequestFactory> saleRequestFactoryKafkaTemplate() {
return new KafkaTemplate<>(saleRequestFactoryProducerFactory());
}
@Bean
public KafkaTemplate<String, String> kafkaTemplate() {
return new KafkaTemplate<>(producerFactory());
}
}
发送对象:
@Autowired
private KafkaTemplate<String, SaleRequestFactory> saleRequestFactoryKafkaTemplate;
private static String topic = "tp-sale";
private void perform(){
SaleRequestFactory obj = new SaleRequestFactory();
obj.setId(100);
ListenableFuture<SendResult<String, SaleRequestFactory>> send = saleRequestFactoryKafkaTemplate.send(topic, obj);
}
消费者:
@EnableKafka
@Configuration
public class KafkaConsumerConfig {
@Value(value = "${kafka.bootstrapAddress}")
private String bootstrapAddress;
private String groupId = "test";
@Bean
public ConsumerFactory<String, SaleResponseFactory> consumerFactory() {
Map<String, Object> props = new HashMap<>();
props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, SaleResponseFactory.class);
return new DefaultKafkaConsumerFactory<>(props);
}
@Bean
public ConcurrentKafkaListenerContainerFactory<String, SaleResponseFactory> kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory<String, SaleResponseFactory> factory =
new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory());
return factory;
}
}
//接收对象
@KafkaListener(topics = "tp-sale")
public SaleResponseFactory transactionElavonAuthorizeProcess(@Payload SaleRequestFactory tf, @Headers MessageHeaders headers) throws Exception {
System.out.println(tf.getId());
SaleResponseFactory resObj = new SaleResponseFactory();
resObj.setUnique_id("123123");
return resObj;
}
部署生产者时，在部署过程中出现错误:
When I deploy the Producer I get error during deployment:
原因:org.apache.kafka.common.KafkaException:类org.engine.plugin.transactions.factory.SaleResponseFactory不是org.apache.kafka.common.serialization.Deserializer的实例
自定义对象
import org.apache.kafka.common.serialization.Serializer;
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Builder(toBuilder = true)
public class SaleRequestFactory implements Serializable, Serializer {
private static final long serialVersionUID = 1744050117179344127L;
private int id;
@Override
public byte[] serialize(String s, Object o) {
return new byte[0];
}
}
导入org.apache.kafka.common.serialization.Deserializer;@盖特@Setter@NoArgsConstructor@AllArgsConstructor@Builder(toBuilder = true)公共类SaleResponseFactory实现了Serializable，Deserializer {专用静态最终长serialVersionUID = 1744050117179344127L;私有字符串unique_id;@Overridepublic Object deserialize(String s，byte [] bytes){返回null；}}
您知道如何解决此问题吗?
import org.apache.kafka.common.serialization.Deserializer; @Getter @Setter @NoArgsConstructor @AllArgsConstructor @Builder(toBuilder = true) public class SaleResponseFactory implements Serializable, Deserializer { private static final long serialVersionUID = 1744050117179344127L; private String unique_id; @Override public Object deserialize(String s, byte[] bytes) { return null; } }
Do you know how I can fix this issue?
我尝试了此操作:
I tried this:
制作人:
@Configuration
public class KafkaProducerConfig {
@Value(value = "${kafka.bootstrapAddress}")
private String bootstrapAddress;
@Bean
public ProducerFactory<String, SaleRequestFactory> saleRequestFactoryProducerFactory() {
Map<String, Object> configProps = new HashMap<>();
configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
configProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
configProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, SaleRequestFactorySerializer.class);
return new DefaultKafkaProducerFactory<>(configProps);
}
@Bean
public ProducerFactory<String, String> producerFactory() {
Map<String, Object> configProps = new HashMap<>();
configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
return new DefaultKafkaProducerFactory<>(configProps);
}
@Bean
public KafkaTemplate<String, SaleRequestFactory> saleRequestFactoryKafkaTemplate() {
return new KafkaTemplate<>(saleRequestFactoryProducerFactory());
}
@Bean
public KafkaTemplate<String, String> kafkaTemplate() {
return new KafkaTemplate<>(producerFactory());
}
}
发送对象:
@Autowired
private KafkaTemplate<String, SaleRequestFactory> saleRequestFactoryKafkaTemplate;
private static String topic = "tp-sale";
private void perform(){
SaleRequestFactory obj = new SaleRequestFactory();
obj.setId(100);
ListenableFuture<SendResult<String, SaleRequestFactory>> send = saleRequestFactoryKafkaTemplate.send(topic, obj);
}
消费者:
@EnableKafka
@Configuration
public class KafkaConsumerConfig {
@Value(value = "${kafka.bootstrapAddress}")
private String bootstrapAddress;
private String groupId = "test";
@Bean
public ConsumerFactory<String, SaleResponseFactory> consumerFactory() {
Map<String, Object> props = new HashMap<>();
props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, SaleResponseFactoryDeserializer.class);
return new DefaultKafkaConsumerFactory<>(props);
}
@Bean
public ConcurrentKafkaListenerContainerFactory<String, SaleResponseFactory> kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory<String, SaleResponseFactory> factory =
new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory());
return factory;
}
}
//接收对象
@KafkaListener(topics = "tp-sale")
public SaleResponseFactory transactionElavonAuthorizeProcess(@Payload SaleRequestFactory tf, @Headers MessageHeaders headers) throws Exception {
System.out.println(tf.getId());
SaleResponseFactory resObj = new SaleResponseFactory();
resObj.setUnique_id("123123");
return resObj;
}
自定义对象
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Builder(toBuilder = true)
public class SaleRequestFactory implements Serializable{
private static final long serialVersionUID = 1744050117179344127L;
private int id;
}
public class SaleRequestFactorySerializer implements Serializable, Serializer<SaleRequestFactory> {
@Override
public byte[] serialize(String topic, SaleRequestFactory data) {
// convert data to byte[]
ByteArrayOutputStream out = new ByteArrayOutputStream();
try
{
ObjectOutputStream outputStream = new ObjectOutputStream(out);
outputStream.writeObject(data);
out.close();
}
catch (IOException e)
{
e.printStackTrace();
}
return out.toByteArray();
}
}
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Builder(toBuilder = true)
public class SaleResponseFactory implements Serializable{
private static final long serialVersionUID = 1744050117179344127L;
private String unique_id;
}
public class SaleResponseFactoryDeserializer implements Serializable, Deserializer<SaleResponseFactory> {
@Override
public SaleResponseFactory deserialize(String topic, byte[] data) {
// convert data to SaleResponseFactory
SaleResponseFactory saleResponseFactory = null;
try
{
ByteArrayInputStream bis = new ByteArrayInputStream(data);
ObjectInputStream in = new ObjectInputStream(bis);
saleResponseFactory = (SaleResponseFactory) in.readObject();
in.close();
}
catch (IOException | ClassNotFoundException e)
{
e.printStackTrace();
}
return saleResponseFactory;
}
}
当我尝试发送消息时出现错误:
When I try to send message I get error:
Caused by: org.apache.kafka.common.errors.SerializationException: Error deserializing key/value for partition tp-sale-0 at offset 0. If needed, please seek past the record to continue consumption.
Caused by: java.lang.ClassCastException: null
21:27:51.152 [org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1] DEBUG KafkaMessageListenerContainer$ListenerConsumer[debug:296] - Commit list: {}
21:27:51.153 [org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1] ERROR KafkaMessageListenerContainer$ListenerConsumer[error:149] - Consumer exception
java.lang.IllegalStateException: This error handler cannot process 'SerializationException's directly; please consider configuring an 'ErrorHandlingDeserializer' in the value and/or key deserializer
at org.springframework.kafka.listener.SeekUtils.seekOrRecover(SeekUtils.java:145)
at org.springframework.kafka.listener.SeekToCurrentErrorHandler.handle(SeekToCurrentErrorHandler.java:103)
at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.handleConsumerException(KafkaMessageListenerContainer.java:1265)
at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.run(KafkaMessageListenerContainer.java:1022)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.lang.Thread.run(Thread.java:835)
Caused by: org.apache.kafka.common.errors.SerializationException: Error deserializing key/value for partition tp-sale-0 at offset 0. If needed, please seek past the record to continue consumption.
Caused by: java.lang.ClassCastException: null
您知道如何解决此问题吗?
Do you know how I can fix this issue?
我设法实现了这些改进:
I managed to implement these improvements:
制作人:
@Configuration
public class KafkaProducerConfig {
@Value(value = "${kafka.bootstrapAddress}")
private String bootstrapAddress;
@Bean
public ProducerFactory<String, SaleRequestFactory> saleRequestFactoryProducerFactory() {
Map<String, Object> configProps = new HashMap<>();
configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
configProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
configProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, SaleRequestFactorySerializer.class);
return new DefaultKafkaProducerFactory<>(configProps);
}
@Bean
public ProducerFactory<String, String> producerFactory() {
Map<String, Object> configProps = new HashMap<>();
configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
return new DefaultKafkaProducerFactory<>(configProps);
}
@Bean
public KafkaTemplate<String, SaleRequestFactory> saleRequestFactoryKafkaTemplate() {
return new KafkaTemplate<>(saleRequestFactoryProducerFactory());
}
@Bean
public KafkaTemplate<String, String> kafkaTemplate() {
return new KafkaTemplate<>(producerFactory());
}
}
发送对象:
@Autowired
private KafkaTemplate<String, SaleRequestFactory> saleRequestFactoryKafkaTemplate;
private static String topic = "tp-sale";
private void perform(){
SaleRequestFactory obj = new SaleRequestFactory();
obj.setId(100);
ListenableFuture<SendResult<String, SaleRequestFactory>> send = saleRequestFactoryKafkaTemplate.send(topic, obj);
}
消费者:
@EnableKafka
@Configuration
public class KafkaConsumerConfig {
@Value(value = "${kafka.bootstrapAddress}")
private String bootstrapAddress;
private String groupId = "test";
@Bean
public ConsumerFactory<String, SaleResponseFactory> consumerFactory() {
Map<String, Object> props = new HashMap<>();
props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, SaleResponseFactoryDeserializer.class);
return new DefaultKafkaConsumerFactory<>(props);
}
@Bean
public ConcurrentKafkaListenerContainerFactory<String, SaleResponseFactory> kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory<String, SaleResponseFactory> factory =
new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory());
return factory;
}
}
接收对象
@KafkaListener(topics = "tp-sale")
public SaleResponseFactory transactionElavonAuthorizeProcess(@Payload SaleRequestFactory tf, @Headers MessageHeaders headers) throws Exception {
System.out.println(tf.getId());
SaleResponseFactory resObj = new SaleResponseFactory();
resObj.setUnique_id("123123");
return resObj;
}
自定义对象
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Builder(toBuilder = true)
public class SaleRequestFactory implements Serializable{
private static final long serialVersionUID = 1744050117179344127L;
private int id;
}
public class SaleRequestFactorySerializer implements Serializable, Serializer<SaleRequestFactory> {
@Override
public byte[] serialize(String topic, SaleRequestFactory data) {
// convert data to byte[]
ByteArrayOutputStream out = new ByteArrayOutputStream();
try
{
ObjectOutputStream outputStream = new ObjectOutputStream(out);
outputStream.writeObject(data);
out.close();
}
catch (IOException e)
{
e.printStackTrace();
}
return out.toByteArray();
}
}
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Builder(toBuilder = true)
public class SaleResponseFactory implements Serializable{
private static final long serialVersionUID = 1744050117179344127L;
private String unique_id;
}
public class SaleResponseFactoryDeserializer implements Serializable, Deserializer<SaleResponseFactory> {
@Override
public SaleResponseFactory deserialize(String topic, byte[] data) {
// convert data to SaleResponseFactory
SaleResponseFactory saleResponseFactory = null;
try
{
ByteArrayInputStream bis = new ByteArrayInputStream(data);
ObjectInputStream in = new ObjectInputStream(bis);
saleResponseFactory = (SaleResponseFactory) in.readObject();
in.close();
}
catch (IOException | ClassNotFoundException e)
{
e.printStackTrace();
}
return saleResponseFactory;
}
}
当我发送一些消息时出现错误:
When I send some message I get error:
13:03:53.675 [org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1] DEBUG RecordMessagingMessageListenerAdapter[debug:296] - Listener method returned result [org.factory.SaleResponseFactory@69c400ab] - generating response message for it
13:03:53.675 [org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1] DEBUG RecordMessagingMessageListenerAdapter[debug:296] - No replyTopic to handle the reply: org.factory.SaleResponseFactory@69c400ab
您知道我该如何解决这个问题?
Do you know how I can solve this issue?
推荐答案
您要使用的对象类型与序列化对象的类型不同.不知道为什么需要这样做.您可以将反序列化更新为如下所示.
You are using different type to cast the object than what it was serialize with. Not sure why you need to do that. You can update your deserialize to something like below.
public class SaleRequestFactoryDeserializer implements Serializable, Deserializer<SaleRequestFactory> {
@Override
public SaleRequestFactory deserialize(String topic, byte[] data) {
...
saleRequestFactory = (SaleRequestFactory) in.readObject();
}
}
java.lang.ClassCastException: null
这也意味着您的序列化未按预期进行.尝试投射之前，请确保您具有有效的有效载荷.
This also means your serialization didn't work as expected. Make sure you have valid payload before you try to cast.
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