This works fine but AndroidHttpTransport is deprecated:
AndroidHttpTransport t = new AndroidHttpTransport("http://a.com/service.asmx");
t.call(action, envelope);
This gives SSLProtocolException (but I don't want use SSL):
HttpsTransportSE t = new HttpsTransportSE("a.com", 80, "/service.asmx", timeout);
t.call(action, envelope);
HttpTransportSE(String url) should work.