unmarshalling

I am getting this error, while unmarshalling a string. I have created Java files using JAXB. JAXBContext jaxbContext = JAXBContext.newInstance(DocumentType.class); Unmarshaller unmarshaller = jaxbContext.createUnmarshaller(); // Input string posted below DocumentType dType = (DocumentType) unmarshaller.unmarshal(new StringReader("input string")); Stack trace: Exception in thread "main" javax.xml.bind.UnmarshalException: unexpected element (uri:"http://ocrsdk.com/schema/recognizedBusinessCard-1.0.xsd", local:"document"). Expected elements are (none) at com.sun.xml.internal.bind.v2.runtime

I would like to know if it's possible to differenciate a void value and an unspecified field value. Here is an example: var jsonBlob = []byte(`[ {"Name": "A", "Description": "Monotremata"}, {"Name": "B"}, {"Name": "C", "Description": ""} ]`) type Category struct { Name string Description string } var categories []Category err := json.Unmarshal(jsonBlob, &categories) if err != nil { fmt.Println("error:", err) } fmt.Printf("%+v", categories) Also available here: https://play.golang.org/p/NKObQB5j4O Output: [{Name:A Description:Monotremata} {Name:B Description:} {Name:C Description:}] So in this

I am working on a general JSON based message passing protocol in golang. What I would like to do is have a BaseMessage that has general information like Type , timestamp , etc. But at the same time I want to be able to define more specific message structures for certain types of data. For example: type Message struct { Type string `json:type` Timestamp string `json:timestamp` } type EventMessage struct { Message EventType string EventCreator string EventData interface{} } I have a set of handlers and to determine which handler should process the message I decode the JSON to the general Message