title: Spring Boot JMS MappingJackson2MessageConverter cannot find `_type` field even though it exists
body: <p>I'm using Spring boot to receive JMS message and cURL to send it.</p>
  
  <p>Here's the Spring config:</p>
  
  <pre><code>@Bean
  public MessageConverter jsonJmsMessageConverter() {
      MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
      converter.setTargetType(MessageType.TEXT);
      converter.setTypeIdPropertyName("_type");
      return converter;
  }
  </code></pre>
  
  <p>When I try to send a message, I get:</p>
  
  <p><code>org.springframework.jms.support.converter.MessageConversionException: Could not find type id property [_type] on message [ID:b5151b422e8a-41371-1526292561432-6:3:1:1:14] from destination [queue://ssg]</code></p>
  
  <p>My cURL command is:</p>
  
  <p><code>curl -u 'un:pw' -H '_type: com.me.SSMessage' -d 'body={"_type": "com.me.SSMessage", "url": "https://www.google.com"}' "http://localhost:8161/api/message/ssg?type=queue&amp;clientId=consumerA"</code></p>
  
  <p><code>_type</code> is set, both as a header (I don't think this is right) and as a field in the JSON.  Why do I get that error from the Spring app?</p>