org.apache.camel.InvalidPayloadException: No body available of type error thrown while unMarshalling Jaxb Object - jaxb

Question

I am sending JAXB Object to Rabbit MQ via Java.
JAXBContext jaxbContext = JAXBContext.newInstance(MyDTO.class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
// output pretty printed
jaxbMarshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);
java.io.StringWriter sw = new StringWriter();
jaxbMarshaller.marshal(deliveryrequest, sw);
ConnectionFactory factory = new ConnectionFactory() ;
//TODO change the hardcoding to the properties file
factory.setHost("rabbitmq.host.net");
factory.setUsername("user");
factory.setPassword("pass");
Channel channel ;
Connection connection;
Map<String, Object> args = new HashMap<String, Object>();
String haPolicyValue = "all";
args.put("x-ha-policy", haPolicyValue);
connection = factory.newConnection();
channel = connection.createChannel();
//TODO change the hardcoding to the properties file
channel.queueDeclare("upload.com.some.queue", true, false, false, args);
//TODO change the hardcoding to the properties file
channel.basicPublish("com.some.exchange", "someroutingKey",
new AMQP.BasicProperties.Builder().contentType("text/plain")
.deliveryMode(2).priority(1).userId("guest").build(),
sw.toString().getBytes());
I am using Camel in different application to read this.
<camel:route id="myRoute">
<camel:from uri="RabbitMQEndpoint" />
<camel:to uri="bean:MyHandler" />
</camel:route>
Handler is using the Jaxb object redone in camel side
#Handler
public void handleRequest(MyDTO dto) throws ParseException {
I am getting the error which I did not expect to get.
Caused by: org.apache.camel.NoTypeConversionAvailableException: No type converter available to convert from type: byte[] to the required type: com.mycompany.MyDTO with value [B#1b8d3e42
at org.apache.camel.impl.converter.BaseTypeConverterRegistry.mandatoryConvertTo(BaseTypeConverterRegistry.java:181)
at org.apache.camel.impl.MessageSupport.getMandatoryBody(MessageSupport.java:99)
Solution is appreciated.

Answer 1

Your message body type from rabbit is a byte[], and you want to call a bean which as MyDTO type. You have a type mismatch. And Camel cannot find a type converter that can convert the message body from byte[] to your MyDTO type.
Is the byte[] data from Rabbit in XML format? And do you have JAXB annotations on MyDTO classes, so you could use JAXB to marshal that from xml to Java ?

Answer 2

It is Jaxb object. I was under impression that if i move the publisher too Camel. Things will be sorted out.
I changed the publisher to the following.
#EndpointInject(context = "myContext" , uri = "direct:myRoute")
private ProducerTemplate sendAMyContext;
And in method I called
#Override
public MyResponse putMyCall(
MyRequest myrequest) {
sendMyContext.sendBody(myrequest);
My camel route is simple one
<camel:camelContext id="MyContext" autoStartup="true" xmlns="http://camel.apache.org/schema/spring">
<camel:endpoint id="myQueue" uri="${my.queue.1}" />
<camel:route>
<camel:from uri="direct:myRoute"/>
<camel:to uri="bean:mySendHandler"/>
<camel:convertBodyTo type="String"></camel:convertBodyTo>
<camel:to uri="ref:myQueue" />
</camel:route>
</camel:camelContext>
I added the handler to convert the Jaxb object to string(because of error)
public class MySendHandler {
#Handler
public String myDelivery( MyRequest myRequest) throws ParseException, JAXBException {
JAXBContext jaxbContext = JAXBContext.newInstance(MyRequest.class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
// output pretty printed
jaxbMarshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);
java.io.StringWriter sw = new StringWriter();
jaxbMarshaller.marshal(attributedDeliveryRequest, sw);
return sw.toString();
}
Still the same error
[SpringAMQPConsumer.SpringAMQPExecutor-1] WARN org.springframework.amqp.support.converter.JsonMessageConverter (JsonMessageConverter.java:111) - Could not convert incoming message with content-type [text/plain]
SpringAMQPConsumer.SpringAMQPExecutor-1] ERROR org.apache.camel.processor.DefaultErrorHandler (MarkerIgnoringBase.java:161) - Failed delivery for (MessageId: ID-Con ExchangeId: ID-65455-1380873539452-3-2).
Exhausted after delivery attempt: 1 caught: org.apache.camel.CamelExecutionException: Exception occurred during execution on the exchange: Exchange[Message: <XML>]
org.apache.camel.CamelExecutionException: Exception occurred during execution on the exchange: Exchange[Message: <xml>
.....
Caused by: org.apache.camel.InvalidPayloadException: No body available of type: MyDTO but has value: [B#7da255c of type: byte[] on: Message: <xml>
. Caused by: [org.apache.camel.NoTypeConversionAvailableException - No type converter available to convert from type: byte[] to the required type: MyDeliveryDTO with value [B#7da255c]
at org.apache.camel.impl.MessageSupport.getMandatoryBody(MessageSupport.java:101)
at org.apache.camel.builder.ExpressionBuilder$38.evaluate(ExpressionBuilder.java:934)
... 74 more
Caused by: org.apache.camel.NoTypeConversionAvailableException: No type converter available to convert from type: byte[] to the required type: MyDTO with value [B#7da255c
at org.apache.camel.impl.converter.BaseTypeConverterRegistry.mandatoryConvertTo(BaseTypeConverterRegistry.java:181)
at org.apache.camel.impl.MessageSupport.getMandatoryBody(MessageSupport.java:99)
... 75 more
My receiving camel route is as below
<camel:route id="processVDelivery">
<camel:from uri="aVEndpoint" />
<camel:to uri="bean:myDataHandler" />
</camel:route>
I added
<camel:convertBodyTo type="String"></camel:convertBodyTo>
to it and it gave me error that it cannot convert it from string to the object
adding this
<camel:unmarshal></camel:unmarshal>
-------------------------
Answer to the question will be all your mashaller have to be part of classpath
---------------------------------
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-asl</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-jaxrs</artifactId>
<version>${jackson.version}</version>
</dependency>
------- Also you can the custom marshaller using dataformat
<camel:dataFormats>
<camel:jaxb id="name" contextPath="com.something"/>
</camel:dataFormats
make sure that you keep jaxb.index file in com.something package with the root level Jaxb object name

Answer 3

Using Camel Rest with Spring boot
rest("/authenticate")
.post()
.route()
.setHeader("Content-Type", constant("application/json"))
.setHeader("Accept", constant("application/json"))
.setHeader(Exchange.HTTP_METHOD, constant("POST"))
.process(exchange -> {
org.apache.camel.TypeConverter tc = exchange.getContext().getTypeConverter();
String str_value = tc.convertTo(String.class, exchange.getIn().getBody());
System.err.println(str_value);
exchange.getOut().setBody(str_value);
})
//.removeHeader(Exchange.HTTP_URI)
.to("http://localhost:8082/authenticate?bridgeEndpoint=true")
//.convertBodyTo(DTO.class)
.log("Boo!")
.end()
.endRest();