vSphere API to fetch datastore is taking huge time.

Hi below is snippet of code. The last line of the code(which is bold) is call multiple times. Its performance bottle neck for us. Can you suggest ways to improve it?

This code is eventually use to fetch datastore information.

//input parameters: user name - user name on Vsphere

     password - password of user

     hostname - hostname of system.

//create connection to ESX.

//create service refernce

ManagedObjectReference _svcRef = new ManagedObjectReference();

        _svcRef.setType("ServiceInstance");

        _svcRef.set_value("ServiceInstance");

VimServiceLocator _locator = new VimServiceLocator();

            _locator.setMaintainSession(true);

VimPortType   _service = _locator.getVimPort(new URL(urlStr));

ServiceContent  _sic = _service.retrieveServiceContent(_svcRef);

ManagedObjectReference   _propCol = _sic.getPropertyCollector();

ManagedObjectReference   _rootFolder = _sic.getRootFolder();

            if (_sic.getSessionManager() != null) {

                _service.login(_sic.getSessionManager(), username, password, null);

//Create connection to ESX host  - end

//The above menthod is called once during the class instantion.(aka constructor

//this line is call mutiple times to fetch datastore object.

//customer has reported a performance issue with this code. When datastore number is around 100 , it takes around 1+ hour to fetch details.

_service.findByDnsName(_sic.getSearchIndex(),null,hostname,false);