How to Check using HttpResponse, the response body is a SOAP Messages or it is a XML Message or XSD Document or it is a WSDL Document

Question

HttpResponse response = httpClient.execute(new HttpGet(URL));
HttpEntity entity = response.getEntity();
String responseString = new BasicResponseHandler().handleResponse(response);

After this how do we parse responseString to check it is a XML or SOAP Message or XSD Document or a WSDL Document.

Answer 1

Since every SOAP, XSD or WSDL document is also an XML document:

1. Read the entire document into a buffer (or a local file).
2. Parse using a plain XML parser.
3. Examine the DOM (or the events) to decide if the document is SOAP, XSD, WSDL or ... something else.
4. Reparse the buffered document using the relevant parser.