Question

我正在尝试使用Rabbitmq中的标头交换来生成和使用消息。当我尝试生成消息时，我必须将消息转换为byte []，但是在用户方面，我无法对其进行反序列化。我在杰克逊依赖项中使用了classMapper，但仍然无法解码该类。我不确定我是否缺少某些东西或做错了什么。

ProducerConfiguration类

@Configuration
public class RabbitMQConfig 
{

    @Value("${exchangeName}")
    String exchange;

    @Value("${queueName}")
    String queueName;

    @Value("${queueName1}")
    String queueName1;

    @Bean
    public List<Object> topicBindings() 
    {

        Queue headerQueue = new Queue(queueName);
        Queue headerQueue1 = new Queue(queueName1);

        Map<String,Object> mapForQueue = new HashMap<>();
        mapForQueue.put("key", "value");
        mapForQueue.put("key2", "value2");

        Map<String,Object> mapForQueue1 = new HashMap<>();
        mapForQueue.put("key", "value");
        mapForQueue1.put("key1", "value1");

        HeadersExchange headerExchange = new HeadersExchange(exchange);

        return Arrays.asList
                (
                        headerQueue,headerQueue1,headerExchange,
                        BindingBuilder.bind(headerQueue).to(headerExchange).whereAny(mapForQueue),
                        BindingBuilder.bind(headerQueue1).to(headerExchange).whereAll(mapForQueue1)
                );
    }

    @Bean
    public Jackson2JsonMessageConverter jsonMessageConverter() 
    {
        Jackson2JsonMessageConverter jsonConverter = new Jackson2JsonMessageConverter();
        jsonConverter.setClassMapper(classMapper());
        return jsonConverter;
    }

    @Bean
    public DefaultClassMapper classMapper() 
    {
        DefaultClassMapper classMapper = new DefaultClassMapper();
        Map<String, Class<?>> idClassMapping = new HashMap<>();
        idClassMapping.put("String", String.class);
        idClassMapping.put("Employee", Employee.class);
        classMapper.setIdClassMapping(idClassMapping);
        return classMapper;
    }

}

SenderClass

@Service
public class RabbitMQSender 
{
    @Autowired
    private AmqpTemplate amqpTemplate;

    @Value("${exchangeName}")
    private String exchange;

    public void send(Employee employee) 
    { 
        Message message = MessageBuilder.withBody(SerializationUtils.serialize(employee))
                .setHeader("key", "value")
                .setHeader("key1", "value1")
                .build();

        amqpTemplate.convertAndSend(exchange,"",message);
    }

}

ConsumerConfiguration类

@EnableRabbit
@Configuration
public class ConsumerConfiguration
{
    @Bean
    public Jackson2JsonMessageConverter jsonMessageConverter() 
    {
        Jackson2JsonMessageConverter jsonConverter = new Jackson2JsonMessageConverter();
        jsonConverter.setClassMapper(classMapper());
        return jsonConverter;
    }

    @Bean
    public DefaultClassMapper classMapper() 
    {
        DefaultClassMapper classMapper = new DefaultClassMapper();
        Map<String, Class<?>> idClassMapping = new HashMap<>();
        idClassMapping.put("String", String.class);
        idClassMapping.put("Employee", Employee.class);
        classMapper.setIdClassMapping(idClassMapping);
        return classMapper;
    }

}

ConsumerApplication

@Component
@RabbitListener(queues = "#{'${combinedQueue}'.split(';')}")
public class RabbitMqListener 
{
    @RabbitHandler
    public void recievedMessage(@Header(AmqpHeaders.CONSUMER_QUEUE) String rk,@Payload Employee employee) 
    {
        System.out.println("*********************************************************************************************");
        System.out.println("Header recieved  = "+rk);
        System.out.println("Recieved Object Message From Important Queue " + employee);
        System.out.println("*********************************************************************************************");
    }

    @RabbitHandler
    public void recievedMessage1(@Header(AmqpHeaders.CONSUMER_QUEUE) String rk,@Payload byte[] object) 
    {
        System.out.println("*********************************************************************************************");
        System.out.println("Header recieved  = "+rk);

        Employee emp = (Employee)SerializationUtils.deserialize(object);

        System.out.println("Recieved String Message From Important Queue " + emp);
        System.out.println("*********************************************************************************************");
    }

}

员工阶层

public class Employee
{

    private String empName;
    private String empId;

    public String getEmpName() {
        return empName;
    }

    public void setEmpName(String empName) {
        this.empName = empName;
    }

    public String getEmpId() {
        return empId;
    }

    public void setEmpId(String empId) {
        this.empId = empId;
    }

    @Override
    public String toString() {
        return "Employee [empName=" + empName + ", empId=" + empId + "]";
    }

}

ErrorLog

org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Listener method 'public void com.rabbitmq.consumer.service.RabbitMqListener.recievedMessage1(java.lang.String,byte[])' threw exception
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:198) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:127) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:1552) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.actualInvokeListener(AbstractMessageListenerContainer.java:1478) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:1466) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doExecuteListener(AbstractMessageListenerContainer.java:1461) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:1410) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:870) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:854) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1600(SimpleMessageListenerContainer.java:78) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.mainLoop(SimpleMessageListenerContainer.java:1137) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1043) [spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_191]
Caused by: java.lang.IllegalStateException: Could not deserialize object type
    at org.springframework.amqp.utils.SerializationUtils.deserialize(SerializationUtils.java:98) ~[spring-amqp-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.utils.SerializationUtils.deserialize(SerializationUtils.java:75) ~[spring-amqp-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at com.rabbitmq.consumer.service.RabbitMqListener.recievedMessage1(RabbitMqListener.java:32) ~[classes/:na]
    at sun.reflect.GeneratedMethodAccessor42.invoke(Unknown Source) ~[na:na]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:170) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:120) ~[spring-messaging-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.DelegatingInvocableHandler.invoke(DelegatingInvocableHandler.java:130) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.HandlerAdapter.invoke(HandlerAdapter.java:60) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.amqp.rabbit.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:190) ~[spring-rabbit-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    ... 12 common frames omitted
Caused by: java.lang.ClassNotFoundException: com.poc.springbootrabbitmq.model.Employee
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[na:1.8.0_191]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_191]
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) ~[na:1.8.0_191]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_191]
    at java.lang.Class.forName0(Native Method) ~[na:1.8.0_191]
    at java.lang.Class.forName(Class.java:348) ~[na:1.8.0_191]
    at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:686) ~[na:1.8.0_191]
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1868) ~[na:1.8.0_191]
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1751) ~[na:1.8.0_191]
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2042) ~[na:1.8.0_191]
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1573) ~[na:1.8.0_191]
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:431) ~[na:1.8.0_191]
    at org.springframework.amqp.utils.SerializationUtils.deserialize(SerializationUtils.java:92) ~[spring-amqp-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    ... 22 common frames omitted

2019-05-06 00:39:35.801  WARN 2780 --- [ntContainer#0-1] o.s.a.s.c.Jackson2JsonMessageConverter   : Could not convert incoming message with content-type [application/octet-stream], 'json' keyword missing.

此外，我能否以字节[]以外的其他任何格式生成消息？

Answer 1

此外，我能否以字节[]以外的其他任何格式生成消息？

是的，有可能。

Jackson（通常）用于将Java对象转换为Json字符串（即字符数据）。您似乎正在尝试执行此操作，但同时也尝试将类作为二进制数据（byte []）发送。您需要选择一个。

stacktrace正在尝试提供帮助：

java.lang.ClassNotFoundException：com.poc.springbootrabbitmq.model.Employee。找不到要序列化的类，因此甚至尽管它有一条消息，但不知道该怎么办。
osascJackson2JsonMessageConverter：无法转换内容类型为[application / octet-stream]，缺少'json'关键字的传入消息。这是在告诉您，您正在发送二进制内容（和Jackson）感到困惑，因为它期待的是Json即字符数据。

也许这更接近您想要达到的目标？ https://thepracticaldeveloper.com/2016/10/23/produce-and-consume-json-messages-with-spring-boot-amqp/

Answer 2

2019-05-06 00：39：35.801警告2780 --- [ntContainer＃0-1] osascJackson2JsonMessageConverter：无法转换内容类型为[application / octet-stream]的传入消息，缺少'json'关键字

仅当content_type属性包含json（例如application/json）时，杰克逊转换器才会转换。

如何使用标头交换从Rabbitmq

2 个答案: