private boolean login() {
  LoginResult loginResult = null;
  SoapBindingStub sfdc = null;
  try {
    //    Create binding object 
    sfdc = (SoapBindingStub) new SforceServiceLocator().getSoap();
    //    login
    loginResult = sfdc.login("username", "password");
  } catch (Exception ex) {
    System.out.println("An unexpected error has occurred." + ex.getMessage());
    return false;
  }

  System.out.println("Login was successful.");

  //    Reset the SOAP endpoint to the returned server URL
  sfdc._setProperty(SoapBindingStub.ENDPOINT_ADDRESS_PROPERTY, loginResult.getServerUrl());

  //    Create a new session header object
  //    add the session ID returned from the login
  SessionHeader sh = new SessionHeader();
  sh.setSessionId(loginResult.getSessionId());
  //    Set the session header for subsequent call authentication
  sfdc.setHeader(new SforceServiceLocator().getServiceName().getNamespaceURI(),
                       "SessionHeader", sh);

.
.
.
}