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无法反序列化消息，因为我 class 对象即使我在 class 路径中有 class 也没有找到我应该收到的消息。

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 +
                '}';
    }
}

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[=14=]1(SimpleMessageListenerContainer.java:93) [spring-rabbit-1.5.6.RELEASE.jar:na]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.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.access00(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.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，您注册了 jsonMessageConverter，同时您使 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，通过对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，在序列化时，java考虑了class名称、包结构等信息，所以在消费者端我们需要让相同的包structure.I遇到相同的使用 jsonMessageConverter 时出现问题。因此，从我的角度来看，解决此问题的方法是将您的消息对象打包到一个 jar 中，并将该 jar 作为依赖项添加到您的生产者和消费者项目中。

Answer 2

当你使用rabbitmq时，你应该把你的class放在同名包里，如：com.xxx.entity.Order。如果 class 在不同的包中，如 com.xxx.consumer.entity.Order``com.xxx.producer.entity.Order 它将抛出错误。

Answer 3

致那些从 IntelliJ 来到这里但在使用 消息队列时仍未解决此类或类似 ClassNotFoundException 问题的人;很可能您正在处理两个或更多不同的项目，并且您甚至可能将这些项目置于同一根目录下，但您仍然遇到此异常，因为这两个或更多项目未设置为模块IntelliJ 中的单个项目。此外，要序列化 and/or 反序列化对象，RabbitMQ 需要相同的 class，但您可能在不同的项目中有两个看起来相似的 class。

要解决这个问题，您可以采用以下技巧：

在包含“不相交”项目的根文件夹中创建一个新的空项目。
IntelliJ 将提示您将这些项目作为模块导入到这个空项目中； select pom.xml 或 build.gradle 文件以这样导入它们。
按确定，项目将加载到您之前的空项目下。
现在，剩下的就是对这些模块进行分组。您可以按照以下方式执行此操作 - IntelliJ's Guide for Grouping Modules.
将模块分组后，您可以（从不同模块中删除一个或多个 classes - 只留下 class 的一个实现）导入所需的 class 通过向模块添加 Maven 或 Gradle 依赖项来从所需模块中获取。

如果您使用的是 Maven，那么 pom.xml 文件中的依赖项应该如下所示：

<dependency>
    <groupId>com.rabbitmq</groupId>
    <artifactId>commons</artifactId>
    <version>1.0-SNAPSHOT</version>
    <scope>compile</scope>
</dependency>

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

AMQP(RabbitMQ) Could not deserialize object, ClassNotFoundException

java

serialization

amqp

rabbitmq

classnotfoundexception