问题
I want to implement a RabbitMq(AMQP) messaging in java SpringBoot, but when I receive the message it says that the messaGE could not be deserialize because I the class for the object that I supposed to receive was not found even if I have that class int the classpath.
RabbitMqListener.java:
@EnableRabbit
@Component
public class RabbitMqListener {
Logger logger = Logger.getLogger(RabbitMqListener.class);
@RabbitListener(queues = "queue2")
public void processQueue1(Product message) {
logger.info("Received from queue 2: " + message);
}
}
RabbitConfiguration.java:
@Configuration
public class RabbitConfiguration {
Logger logger = Logger.getLogger(RabbitConfiguration.class);
@Bean
public ConnectionFactory connectionFactory() {
CachingConnectionFactory connectionFactory =
new CachingConnectionFactory("localhost");
return connectionFactory;
}
@Bean
public AmqpAdmin amqpAdmin() {
return new RabbitAdmin(connectionFactory());
}
@Bean
public MessageConverter jsonMessageConverter(){
return new JsonMessageConverter();
}
@Bean
public RabbitTemplate rabbitTemplate() {
RabbitTemplate template = new RabbitTemplate(connectionFactory());
template.setMessageConverter(jsonMessageConverter());
return template;
}
@Bean
public Queue myQueue1() {
return new Queue("queue1");
}
@Bean
public Queue myQueue2() {
return new Queue("queue2");
}
}
SampleController.java:
@Controller
public class SampleController {
Logger logger = Logger.getLogger(SampleController.class);
@Autowired
AmqpTemplate template;
@RequestMapping("/emit")
@ResponseBody
String queue1() {
logger.info("Emit to queue1");
template.convertAndSend("queue1","Message to queue 1");
return "Emit to queue 1";
}
}
Product.java:
public class Product implements Serializable{
private Long id;
private String name;
private int stock;
private int price;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getStock() {
return stock;
}
public void setStock(int stock) {
this.stock = stock;
}
public Product() {
}
@Override
public String toString() {
return "Product{" +
"id=" + id +
", name='" + name + '\'' +
", stock=" + stock +
", price=" + price +
'}';
}
}
And the stacktrace:
2016-07-11 09:34:02.840 WARN [order-service,,,] 4084 --- [cTaskExecutor-1] s.a.r.l.ConditionalRejectingErrorHandler : Execution of Rabbit message listener failed.
org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Listener threw exception
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.wrapToListenerExecutionFailedExceptionIfNeeded(AbstractMessageListenerContainer.java:865) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:760) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:680) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$001(SimpleMessageListenerContainer.java:93) [spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$1.invokeListener(SimpleMessageListenerContainer.java:183) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.invokeListener(SimpleMessageListenerContainer.java:1358) [spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:661) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:1102) [spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:1086) [spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1100(SimpleMessageListenerContainer.java:93) [spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1203) [spring-rabbit-1.5.6.RELEASE.jar:na]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_91]
Caused by: java.lang.IllegalStateException: Could not deserialize object type
at org.springframework.amqp.utils.SerializationUtils.deserialize(SerializationUtils.java:82) ~[spring-amqp-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.support.converter.SimpleMessageConverter.fromMessage(SimpleMessageConverter.java:110) ~[spring-amqp-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.adapter.AbstractAdaptableMessageListener.extractMessage(AbstractAdaptableMessageListener.java:185) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter$MessagingMessageConverterAdapter.extractPayload(MessagingMessageListenerAdapter.java:173) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.support.converter.MessagingMessageConverter.fromMessage(MessagingMessageConverter.java:118) ~[spring-amqp-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.toMessagingMessage(MessagingMessageListenerAdapter.java:102) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:88) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:757) ~[spring-rabbit-1.5.6.RELEASE.jar:na]
... 10 common frames omitted
Caused by: java.lang.ClassNotFoundException: com.productservice.model.Product
at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_91]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_91]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_91]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_91]
at org.springframework.util.ClassUtils.forName(ClassUtils.java:250) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.core.ConfigurableObjectInputStream.resolveClass(ConfigurableObjectInputStream.java:75) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.amqp.support.converter.SimpleMessageConverter$1.resolveClass(SimpleMessageConverter.java:179) ~[spring-amqp-1.5.6.RELEASE.jar:na]
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1620) ~[na:1.8.0_91]
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1521) ~[na:1.8.0_91]
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1781) ~[na:1.8.0_91]
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353) ~[na:1.8.0_91]
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:373) ~[na:1.8.0_91]
at org.springframework.amqp.utils.SerializationUtils.deserialize(SerializationUtils.java:76) ~[spring-amqp-1.5.6.RELEASE.jar:na]
... 17 common frames omitted
Process finished with exit code -1
回答1:
In the code snippet you have registered jsonMessageConverter and at the same time you are making your Person.java serializable. You should either use serialization or the json approach. Moreover the problem lies in the package structure of Person.java. I encountered the same problem, resolved it by taking same package structure for the object being transferred in producer and consumer. The reason behind this is that while serialization, java takes class name , package structure and other information into account, so at the consumer side we need to have the same package structure.I encountered the same problem while using jsonMessageConverter. So from my viewpoint the solution to this problem is to package your message objects into a jar and add that jar as a dependency in your producer and consumer project.
来源：https://stackoverflow.com/questions/38300784/amqprabbitmq-could-not-deserialize-object-classnotfoundexception