Binding a Generic Java Class to a JSON using JAXB - json

Question

I have the following java class
#XmlRootElement
#XmlSeeAlso(DataClass.class)
public static class EnvelopeClass<T> {
#XmlElement
public String version;
#XmlElement
public T data;
EnvelopeClass() {
}
EnvelopeClass(String version, T data) {
this.version = version;
this.data = data;
}
}
#XmlRootElement
public static class DataClass {
#XmlElement
public String name;
DataClass() {
}
DataClass(String name) {
this.name = name;
}
}
I'm creating its instance and marshaling it to json
EnvelopeClass<DataClass> dataClassEnvelopeClass = new EnvelopeClass<DataClass>("1.0", new DataClass("myName"));
I have next result:
{"version":"1.0","data":{"#type":"dataClass","name":"myName"}}
I do not want to have type type information in the json "#type":"dataClass", in other words I want to have next result:
{"version":"1.0","data":{"name":"myName"}}
Exactly this result I have when EnvelopeClass doesn't have Generics.
Is there a way to do this?

Answer 1

To get the desired behaviour, you can use #XmlAnyElement on the data property instead of #XmlElement. For the #XmlAnyElement property the value will correspond to a class with the matching #XmlRootElement annotation.
EnvelopeClass
import javax.xml.bind.annotation.XmlAnyElement;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlSeeAlso;
#XmlRootElement
#XmlSeeAlso(DataClass.class)
public class EnvelopeClass<T> {
#XmlElement
public String version;
#XmlAnyElement
public T data;
EnvelopeClass() {
}
EnvelopeClass(String version, T data) {
this.version = version;
this.data = data;
}
}
DataClass
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
#XmlRootElement(name="data")
public class DataClass {
#XmlElement
public String name;
DataClass() {
}
DataClass(String name) {
this.name = name;
}
}
Demo
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
public class Demo {
public static void main(String[] args) throws Exception {
JAXBContext jc = JAXBContext.newInstance(EnvelopeClass.class);
DataClass data = new DataClass("myName");
EnvelopeClass envelope = new EnvelopeClass<DataClass>("1.0", data);
Marshaller marshaller = jc.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.marshal(envelope, System.out);
}
}