JAXB

The following example uses a named DataFormat of jaxb which is configured with a Java package name to initialize the JAXBContext.

You can, if you prefer, use a named reference to a data format which can then be defined in your Registry such as via your Spring XML file. e.g.

The following example shows how to configure the JaxbDataFormat and use it in multiple routes.

It is possible to use this data format with more than one context path. You can specify multiple context paths using : as a separator, for example com.mycompany:com.mycompany2.

JAXB 2 supports marshalling and unmarshalling XML tree fragments. By default, JAXB looks for the @XmlRootElement annotation on a given class to operate on the whole XML tree. This is useful, but not always. Sometimes the generated code does not have the @XmlRootElement annotation, and sometimes you need to unmarshall only part of the tree.

In that case, you can use partial unmarshalling. To enable this behavior, you need set property partClass on the JaxbDataFormat. Camel will pass this class to the JAXB unmarshaller. If JaxbConstants.JAXB_PART_CLASS is set as one of the exchange headers, its value is used to override the partClass property on the JaxbDataFormat.

For marshalling you have to add the partNamespace attribute with the QName of the destination namespace.

If JaxbConstants.JAXB_PART_NAMESPACE is set as one of the exchange headers, its value is used to override the partNamespace property on the JaxbDataFormat.

While setting partNamespace through JaxbConstants.JAXB_PART_NAMESPACE, please note that you need to specify its value in the format {namespaceUri}localPart, as per the example below.

JaxbDataFormat has a property named fragment which can set the Marshaller.JAXB_FRAGMENT property on the JAXB Marshaller. If you don’t want the JAXB Marshaller to generate the XML declaration, you can set this option to be true. The default value of this property is false.

JaxbDataFormat supports ignoring Non-XML Characters, you need to set the filterNonXmlChars property to true. The JaxbDataFormat will replace any non-XML character with a space character (" ") during message marshalling or unmarshalling. You can also set the Exchange property Exchange.FILTER_NON_XML_CHARS.

This feature has been tested with Woodstox 3.2.9 and Sun JDK 1.6 StAX implementation.

JaxbDataFormat now allows you to customize the XMLStreamWriter used to marshal the stream to XML. Using this configuration, you can add your own stream writer to completely remove, escape, or replace non-XML characters.

The following example shows using the Spring DSL and also enabling Camel’s non-XML filtering:

If you use XJC to create the java class from the schema, you will get an ObjectFactory for your JAXB context. Since the ObjectFactory uses JAXBElement to hold the reference of the schema and element instance value, JaxbDataformat will ignore the JAXBElement by default, and you will get the element instance value instead of the JAXBElement object from the unmarshaled message body.

If you want to get the JAXBElement object form the unmarshaled message body, you need to set the JaxbDataFormat ignoreJAXBElement property to be false.

You can set the encoding option on the JaxbDataFormat to configure the Marshaller.JAXB_ENCODING encoding property on the JAXB Marshaller.

You can set up which encoding to use when you declare the JaxbDataFormat. You can also provide the encoding in the Exchange property Exchange.CHARSET_NAME. This property will override the encoding set on the JaxbDataFormat.

When marshalling using JAXB or SOAP then the JAXB implementation will automatically assign namespace prefixes, such as ns2, ns3, ns4 etc. To control this mapping, Camel allows you to refer to a map which contains the desired mapping.

For example, in Spring XML we can define a Map with the mapping. In the mapping file below, we map SOAP to use soap as a prefix. While our custom namespace http://www.mycompany.com/foo/2 is not using any prefix.

To use this in JAXB or SOAP data formats, you refer to this map, using the namespacePrefixRef attribute as shown below. Then Camel will look up in the Registry a java.util.Map with the id myMap, which was what we defined above.

The JaxbDataFormat supports validation by marshalling and unmarshalling from / to XML. You can use the prefix classpath:, file: or http: to specify how the resource should be resolved. You can separate multiple schema files by using the , character.

Using the Java DSL, you can configure it in the following way:

You can do the same using the XML DSL:

The JaxbDataFormat supports to specify the SchemaLocation when marshalling the XML.

Using the Java DSL, you can configure it in the following way:

You can do the same using the XML DSL:

The JAXB marshaller requires that the message body is JAXB compatible, e.g., it is a JAXBElement, a java instance that has JAXB annotations, or extends JAXBElement. There can be situations where the message body is already in XML, e.g., from a String type.

JaxbDataFormat has an option named mustBeJAXBElement which you can set to false to relax this check and have the JAXB marshaller only attempt marshalling on JAXBElement (javax.xml.bind.JAXBIntrospector#isElement returns true). In those situations, the marshaller will fall back to marshal the message body as-is.