I don't see any major issue in your code. But while you setPreference
for the FirefoxProfile
Class do remember to add all the relevant Multipurpose Internet Mail Extensions
of CSV type files referred in this site.
Here is your own code block with some simple tweaks added to it:
String downloadFilepath = "C:\\Utility\\OP_Resources\\MozillaFirefoxDownload";
System.setProperty("webdriver.gecko.driver", "C:\\Utility\\BrowserDrivers\\geckodriver.exe");
FirefoxProfile Profile = new FirefoxProfile();
Profile.setPreference("browser.download.dir",downloadFilepath);
Profile.setPreference("browser.download.folderList",2);
//neverAsk - saveToDisk - CSV
Profile.setPreference("browser.helperApps.neverAsk.saveToDisk", "application/csv,application/excel,application/vnd.ms-excel,application/vnd.msexcel,text/anytext,text/comma-separated-values,text/csv,text/plain,text/x-csv,application/x-csv,text/x-comma-separated-values,text/tab-separated-values");
//neverAsk - saveToDisk - ANY
Profile.setPreference("browser.helperApps.neverAsk.saveToDisk", "application/xml,text/plain,text/xml,image/jpeg,application/octet-stream");
Profile.setPreference("browser.download.manager.showWhenStarting",false);
//neverAsk - openFile - CSV
Profile.setPreference("browser.helperApps.neverAsk.openFile","application/csv,application/excel,application/vnd.ms-excel,application/vnd.msexcel,text/anytext,text/comma-separated-values,text/csv,text/plain,text/x-csv,application/x-csv,text/x-comma-separated-values,text/tab-separated-values");
//neverAsk - openFile - ANY
Profile.setPreference("browser.helperApps.neverAsk.openFile","application/xml,text/plain,text/xml,image/jpeg,application/octet-stream");
Profile.setPreference("browser.helperApps.alwaysAsk.force", false);
I have verified my code on this site and Microsoft site as well and seems to me works fine.