AMQP(RabbitMQ) 无法反序列化对象，ClassNotFoundException

Question

我想在 java SpringBoot 中实现 RabbitMq(AMQP) 消息传递，但是当我收到消息时，它说消息无法反序列化，因为我没有找到我应该接收的对象的类，即使我有该类int 类路径。

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);
    }

}

兔子配置.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");
    }

}

示例控制器.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";
    }
}

产品.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 +
                '}';
    }
}

和堆栈跟踪：

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

Answer 1

在代码片段中，您已经注册了 jsonMessageConverter，同时您正在使 Person.java 可序列化。您应该使用序列化或 json 方法。而且问题出在Person.java的包结构上。我遇到了同样的问题，通过为生产者和消费者中传输的对象采用相同的包结构来解决它。这背后的原因是，java在序列化时考虑了类名、包结构等信息，所以在消费者端我们需要有相同的包结构。我在使用jsonMessageConverter时遇到了同样的问题。因此，从我的角度来看，此问题的解决方案是将消息对象打包到 jar 中，并将该 jar 添加为生产者和消费者项目中的依赖项。

Answer 2

当你使用 时rabbitmq，你应该将你的类放在同名包中，例如 : com.xxx.entity.Order。如果类位于不同的包中，com.xxx.consumer.entity.Order``com.xxx.producer.entity.Order则会抛出错误。