Question

I want to make generic function that return Object representation of XML document (using JAXB). I need to pass “class” object to JAXBContext constructor, but how I can get it from T?

public <T> readXmlToObject(String xmlFileName, T  jaxbClass) {
   JAXBContext context = JAXBContext.newInstance(T.class); // T.class - here error, how to get it?
   .......
}

Answer 1

Pass the class object instead and it’s easy.

public <T> T readXmlToObject(String xmlFileName, Class<T>  jaxbClass) {
       JAXBContext context = JAXBContext.newInstance( jaxbClass ); // T.class - here error, how to get it?
       Object o = context.createUnmarshaller().unmarshal( new File( xmlFileName ) );
       return jaxbClass.cast( o );
}

The idea here is that since you can’t extract the type parameter from the object, you have to do it the other way around: start with the class and then manipulate the object to match the type parameter.