Pojo to xsd generation

JAXB 2.0 allows you to create a XML schema from an annotated Java class.

You'll find some examples at the AMIS blog and at the JavaPassion site.

Here is how I would do it:

public static void pojoToXSD(Class<?> pojo, OutputStream out) throws IOException, TransformerException, JAXBException {
    JAXBContext context = JAXBContext.newInstance(pojo);
    final List<DOMResult> results = new ArrayList<>();

    context.generateSchema(new SchemaOutputResolver() {

        @Override
        public Result createOutput(String ns, String file)
                throws IOException {
            DOMResult result = new DOMResult();
            result.setSystemId(file);
            results.add(result);
            return result;
        }
    });

    DOMResult domResult = results.get(0);

    // Use a Transformer for output
    TransformerFactory tFactory = TransformerFactory.newInstance();
    Transformer transformer = tFactory.newTransformer();

    DOMSource source = new DOMSource(domResult.getNode());
    StreamResult result = new StreamResult(out);
    transformer.setOutputProperty(OutputKeys.INDENT, "yes");
    transformer.transform(source, result);
}

How to use the method above

try {
        ByteArrayOutputStream stream = new ByteArrayOutputStream();

        pojoToXSD(NESingleResponse.class, stream);

        String finalString = new String(stream.toByteArray());
        System.out.println(finalString);
    } catch (JAXBException ex) {
        Logger.getLogger(NewClass.class.getName()).log(Level.SEVERE, null, ex);
    }

JiBX does this

The schema generator tool first reads one or more JiBX binding definitions and then uses reflection to interpret the structure of the Java classes referenced in the bindings. By combining the binding definitions with the actual class information the schema generator is able to construct one or more XML schemas to represent the documents handled by the bindings.