使用 Spring 和 ActiveMQ 的监听器方法反复抛出“属性名称不能为空”警告

Question

我尝试在两个地方使用 Spring 来实现 ActiveMQ。两种实现都存在这个问题。使用邮递员发送 HTTP 请求或直接在 ActiveMQ 控制台中输入消息会导致无限重复以下错误：

`2024-02-02T17:08:56.317-06:00 ERROR 2264 --- [ntContainer#0-1] c.j.a.config.JmsConfig$JMSErrorHandler   : Error in listener

org.springframework.jms.listener.adapter.ListenerExecutionFailedException: Listener method 'public void com.jackhodge.activemqlearning.consumer.component.MessageConsumer.messageListener(com.jackhodge.activemqlearning.model.SystemMessage)' threw exceptionat org.springframework.jms.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:118) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.adapter.MessagingMessageListenerAdapter.onMessage(MessagingMessageListenerAdapter.java:84) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:783) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:741) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.AbstractMessageListenerContainer.doExecuteListener(AbstractMessageListenerContainer.java:719) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.AbstractPollingMessageListenerContainer.doReceiveAndExecute(AbstractPollingMessageListenerContainer.java:333) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.AbstractPollingMessageListenerContainer.receiveAndExecute(AbstractPollingMessageListenerContainer.java:270) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.invokeListener(DefaultMessageListenerContainer.java:1258) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.executeOngoingLoop(DefaultMessageListenerContainer.java:1248) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.run(DefaultMessageListenerContainer.java:1141) ~[spring-jms-6.1.3.jar:6.1.3]at java.base/java.lang.Thread.run(Thread.java:840) ~[na:na]Caused by: java.lang.NullPointerException: Property name cannot be nullat org.apache.activemq.command.ActiveMQMessage.getObjectProperty(ActiveMQMessage.java:575) ~[activemq-client-jakarta-5.18.3.jar:5.18.3]at org.apache.activemq.command.ActiveMQMessage.getStringProperty(ActiveMQMessage.java:683) ~[activemq-client-jakarta-5.18.3.jar:5.18.3]at org.springframework.jms.support.converter.MappingJackson2MessageConverter.getJavaTypeForMessage(MappingJackson2MessageConverter.java:456) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.support.converter.MappingJackson2MessageConverter.fromMessage(MappingJackson2MessageConverter.java:241) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.adapter.AbstractAdaptableMessageListener.extractMessage(AbstractAdaptableMessageListener.java:250) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.adapter.AbstractAdaptableMessageListener$MessagingMessageConverterAdapter.extractPayload(AbstractAdaptableMessageListener.java:472) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.adapter.AbstractAdaptableMessageListener$MessagingMessageConverterAdapter$LazyResolutionMessage.unwrapPayload(AbstractAdaptableMessageListener.java:539) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.jms.listener.adapter.AbstractAdaptableMessageListener$MessagingMessageConverterAdapter$LazyResolutionMessage.getPayload(AbstractAdaptableMessageListener.java:521) ~[spring-jms-6.1.3.jar:6.1.3]at org.springframework.messaging.handler.annotation.support.PayloadMethodArgumentResolver.resolveArgument(PayloadMethodArgumentResolver.java:122) ~[spring-messaging-6.1.3.jar:6.1.3]at org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:118) ~[spring-messaging-6.1.3.jar:6.1.3]at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:147) ~[spring-messaging-6.1.3.jar:6.1.3]at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:115) ~[spring-messaging-6.1.3.jar:6.1.3]at org.springframework.jms.listener.adapter.MessagingMessageListenerAdapter.invokeHandler(MessagingMessageListenerAdapter.java:110) ~[spring-jms-6.1.3.jar:6.1.3]... 10 common frames omitted`

最引人注目的是

Error in listener [...] Property name cannot be null

.

当我不在监听器中执行任何操作，并且消息监听器中的日志/断点未发送或激活时，错误仍然发生。

这是发生错误的简单应用程序：

JmsConfig

`@Configuration@EnableJmspublic class JmsConfig {

Logger logger = LoggerFactory.getLogger(JMSErrorHandler.class);

@Bean
public DefaultJmsListenerContainerFactory jmsListenerContainerFactory(
        ConnectionFactory connectionFactory,
        DefaultJmsListenerContainerFactoryConfigurer configurer,
        JMSErrorHandler defaultErrorHandler
){
    DefaultJmsListenerContainerFactory jmsListenerContainerFactory = new DefaultJmsListenerContainerFactory();

    jmsListenerContainerFactory.setConnectionFactory(connectionFactory);
    jmsListenerContainerFactory.setConcurrency("1"); // start w/ 5 consumers; auto-scale to 10 consumers as necessary

    jmsListenerContainerFactory.setErrorHandler(defaultErrorHandler);
    jmsListenerContainerFactory.setMessageConverter(this.jacksonJmsMessageConverter());

    configurer.configure(jmsListenerContainerFactory, connectionFactory);
    return jmsListenerContainerFactory;

}


@Service
public class JMSErrorHandler implements ErrorHandler {
    @Override
    public void handleError(Throwable t){
        logger.error("Error in listener ", t);
    }
}

@Bean
public MessageConverter jacksonJmsMessageConverter(){
    MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
    converter.setTargetType(MessageType.TEXT);
    converter.setObjectMapper(new ObjectMapper());
    return converter;
}

发布控制器

`package com.jackhodge.activemqlearning.controller;

import com.jackhodge.activemqlearning.model.SystemMessage;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.http.HttpStatus;import org.springframework.http.ResponseEntity;import org.springframework.jms.core.JmsTemplate;import org.springframework.web.bind.annotation.PostMapping;import org.springframework.web.bind.annotation.RequestBody;import org.springframework.web.bind.annotation.RestController;

@RestControllerpublic class PublishController {// helperclass for sending/receiving messages

// Spring JMS abstraction API: Distills and simplifies process; abstracts away boilerplate code
private JmsTemplate jmsTemplate;

@Autowired
public PublishController(JmsTemplate jmsTemplate) {
    this.jmsTemplate = jmsTemplate;
}

// post method to trigger publishing of messages
// Requests to here at sent to the Messaging Broker
@PostMapping("/publishMessage")
public ResponseEntity<String> publishMessage(@RequestBody SystemMessage systemMessage){
    try{
        jmsTemplate.convertAndSend("jackhodge-queue", systemMessage.toString());
        return new ResponseEntity<>("I, Jack Hodge, sent your message.", HttpStatus.OK);
    } catch (Exception e){
        return new ResponseEntity<>(e.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
    }

}

}

系统消息

`package com.jackhodge.activemqlearning.model;

import lombok.Setter;import org.springframework.beans.factory.annotation.Autowired;

//import java.io.Serializable;

@Setterpublic class SystemMessage{

private String source;
private String message;

public SystemMessage(String source, String message) {

    this.source = source;
    this.message = message;
}


@Override
public String toString() {
    return "SystemMessage{" +
            "source='" + source + '\'' +
            ", message='" + message + '\'' +
            '}';
}

} `

留言消费者

`package com.jackhodge.activemqlearning.consumer.component;

import com.jackhodge.activemqlearning.model.SystemMessage;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.jms.annotation.JmsListener;import org.springframework.stereotype.Component;

@Componentpublic class MessageConsumer {

public static final Logger LOGGER = LoggerFactory.getLogger(MessageConsumer.class);

// Consumes from the Messaging broker
@JmsListener(destination = "jackhodge-queue")
public void messageListener(SystemMessage systemMessage){
    LOGGER.info("Message Received {}", systemMessage);
}

} `

我对 Swing 和 ActiveMQ 有点陌生，这个问题困扰着我——我已经尝试过所有我能想到的断点/日志记录/消息源途径。谢谢！

通过 Postman 和 ActiveMQ 控制台发送此请求都会导致相同的错误，无论如何：

{     
    "source":"jeff bezo",     
    "message":"hello" 
}

Answer 1

我能够使用以下型号发送消息。

@Setter
public class SystemMessage implements Serializable {
    private String source;
    private String message;

    public SystemMessage(String source, String message) {

        this.source = source;
        this.message = message;
    }


    @Override
    public String toString() {
        return "SystemMessage{" +
                "source='" + source + '\'' +
                ", message='" + message + '\'' +
                '}';
    }
}