Connecting to a web service over a Secure Sockets Layer (SSL): protocol:

Android default HttpClinet does not support SSL connections, so if you have a secured web service, you need to connect to it via javax.net.ssl.HttpsURLConnection.
if you want to call a SSL SOAP web service:

String CallWebService(String url,
    String soapAction,
   String envelope) throws IOException  {
  URL address=new URL(url);
  URLConnection connection=address.openConnection();
  HttpsURLConnection post=(HttpsURLConnection)connection;
  post.setDoInput(true);
  post.setDoOutput(true);
  post.setRequestMethod("POST");
  post.setRequestProperty("SOAPAction", soapAction);
  post.setRequestProperty( "Content-type", "text/xml; charset=utf-8" );
  post.setRequestProperty( "Content-Length", String.valueOf(envelope.length()));
  post.setReadTimeout(4000);
  
  OutputStream outStream=post.getOutputStream();
  Writer out=new OutputStreamWriter(outStream);
  out.write(envelope);
  out.flush();
  out.close();
  
  
  InputStream inStream = post.getInputStream();
  BufferedInputStream in = new BufferedInputStream(inStream,4);
  StringBuffer buffer=new StringBuffer();
  // read 4 bytes a time
  byte[] buffArray=new byte[4];
  int c=0;
   while((c=in.read(buffArray))!=-1){
    for(int i=0;i<c;i++)
     buffer.append((char)buffArray[i]);
   }

   return buffer.toString();
 }