如何使用convertSendAndReceive（）方法反序列化消息？由于无法在另一个包中找到反序列化所需的类，它给我NullPointerException。包在代码中被标记。

监听程序正常接收和发送消息

package org.dneversky.user;

@EnableRabbit
@Component
public class TestListener {

  private static final Logger logger = LoggerFactory.getLogger(TestListener.class);

  @Autowired
  private RabbitTemplate rabbitTemplate;

  @RabbitListener(queues = RabbitMQConfig.RECEIVE_QUEUE)
  public void doGet(UserReplyMessage message) {
    logger.info("Received message: {}", message);
    UserReplyMessage response = new UserReplyMessage();
    logger.info("Sending message: {}", response);
    rabbitTemplate.convertSendAndReceive(RabbitMQConfig.RPC_EXCHANGE, 
RabbitMQConfig.REPLY_QUEUE, response);
  }
}

监听程序的配置

package org.dneversky.user.config;

@Configuration
public class RabbitMQConfig {

  public static final String RECEIVE_QUEUE = "rpc_queue";
  public static final String REPLY_QUEUE = "reply_queue";
  public static final String RPC_EXCHANGE = "rpc_exchange";

  @Bean
  public TopicExchange rpcExchange() {
    return new TopicExchange(RPC_EXCHANGE);
  }

  @Bean
  public Queue receiveQueue() {
    return new Queue(RECEIVE_QUEUE);
  }

  @Bean
  public Queue replyQueue() {
    return new Queue(REPLY_QUEUE);
  }

  @Bean
  public Binding receiveBinding() {
    return BindingBuilder.bind(receiveQueue()).to(rpcExchange()).with(RECEIVE_QUEUE);
  }

  @Bean
  public MessageConverter jsonMessageConverter() {
    return new Jackson2JsonMessageConverter();
  }
}

发送方正常发送消息，但无法反序列化返回消息

package org.dneversky.gateway.servie.impl;

@Service
public class UserServiceImpl {

  private static final Logger logger = LoggerFactory.getLogger(UserServiceImpl.class);

  @Autowired
  private RabbitTemplate rabbitTemplate;

  public UserPrincipal getUserByUsername(String username) {
    UserResponse message = new UserResponse(username);
    logger.info("Sending created message: {}", message);
    UserResponse result = (UserResponse)     rabbitTemplate.convertSendAndReceive(RabbitMQConfig.RPC_EXCHANGE, RabbitMQConfig.RPC_QUEUE, message);
    logger.info("Getting response: {}", result);

    return null;
  }
}

发送方配置

package org.dneversky.gateway.config;

@Configuration
public class RabbitMQConfig {

  public static final String RPC_QUEUE = "rpc_queue";
  public static final String REPLY_QUEUE = "reply_queue";
  public static final String RPC_EXCHANGE = "rpc_exchange";

  @Bean
  public Queue rpcQueue() {
    return new Queue(RPC_QUEUE);
  }

  @Bean
  public Queue replyQueue() {
    return new Queue(REPLY_QUEUE);
  }

  @Bean
  public TopicExchange rpcExchange() {
    return new TopicExchange(RPC_EXCHANGE);
  }

  @Bean
  public Binding binding() {
    return BindingBuilder.bind(replyQueue()).to(rpcExchange()).with(REPLY_QUEUE);
  }

  @Bean
  public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
    RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
    rabbitTemplate.setExchange(RPC_EXCHANGE);
    rabbitTemplate.setReplyAddress(REPLY_QUEUE);
    rabbitTemplate.setReplyTimeout(6000);
    rabbitTemplate.setMessageConverter(messageConverter());

    return rabbitTemplate;
  }

  @Bean
  public MessageConverter messageConverter() {
    return new Jackson2JsonMessageConverter();
  }

  @Bean
  public SimpleMessageListenerContainer replyContainer(ConnectionFactory connectionFactory) {
    SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
    container.setConnectionFactory(connectionFactory);
    container.setQueueNames(REPLY_QUEUE);
    container.setMessageListener(rabbitTemplate(connectionFactory));
    return container;
  }
}

错误日志

2016年12月26日，北京市公安局海淀分局备案（京公网安备110802015466）。路径为[]的上下文中的servlet [dispatcherServlet]的Servlet.service（）引发了异常错误[请求处理失败;如果您在运行时遇到一个嵌套的异常，则会出现以下错误：无法解析类名。找不到类[org.dneversky.user.model.UserReplyMessage]]，根本原因为

java.lang.ClassNotFoundException: org.dneversky.user.model.UserReplyMessage