Remove xsi:type information from xml/json JAXB?

Question

I am using JAXB to convert my domain-model to XML and JSON representations. I have Student pojo to convert to XMl/JSON. It has an content property which can be of any data type.

Schema definition for it:

<xs:element name="content" type="xs:anyType" />

Thus the java file generated has Object type for content.

Student.java:

 @XmlAccessorType(XmlAccessType.FIELD)
    @XmlType(name = "", propOrder = {
        "content"
    })
    @XmlRootElement(name = "student")
    public class Student
        extends People
    {
        ................

        @XmlElement(required = true)
        protected Object content;

    }

I marshall using the following code:

Marshall:

    Map<String, Object> properties = new HashMap<String, Object>(1);
                properties.put(JAXBContextProperties.OXM_METADATA_SOURCE, "name-binding.xml");


   this.ctx = JAXBContext.newInstance("packagename",
   packagename.ObjectFactory.class.getClassLoader(), properties);

   Marshaller marshaller = ctx.createMarshaller();

    marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
         marshaller.setProperty(MarshallerProperties.MEDIA_TYPE,media-type);
        marshaller.setProperty(MarshallerProperties.JSON_INCLUDE_ROOT,true);
        marshaller.setProperty(MarshallerProperties.JSON_REDUCE_ANY_ARRAYS, true);

        StringWriter sw = new StringWriter();
        marshaller.marshal(object, sw);

XML:

<student>

    <name>Jack n Jones</name>
    <content xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xsd:string">Sid</content>

</student>

xmlns:xsi and xsi:type="xsd:string"> are coming appended in the content element. I don't want this type information in my XML.

Similarly for JSON it adds the type info:

JSON:

        {
           "name" : "Jack n Jones",
           "content" : {
               "type" : "string",
               "value" : "Sid"
            }
         }

How can I remove the type information and generate XML/JSON according to it's type at run time. So whatever type is content it get's converted to the type without type information

For example if content is String then XML:

 <student>

        <name>Jack n Jones</name>
        <content>Sid</content>

    </student>

Answer 1

Passing an java.lang.Object parameter in and JAXB annotated pojo and having no additionally generated meta information after marshalling is not possible. Since the Object is "unknown" type, it needs to be detected and converted during marshalling process, and the metadata will always be generated by the default marshaller. From this point on, you have three options:

1. White your custom marshaller or adapter (there are plenty examples in WEB)
2. Use String instead of Object (fast and clean solution)
3. If you really must use something generic, use "Element" (https://jaxb.java.net/nonav/2.2.4/docs/api/javax/xml/bind/annotation/XmlAnyElement.html)