File file = new File ("files\\youtube.crx");

ChromeOptions options = new ChromeOptions();

options.addExtensions(file);

WebDriver driver = new ChromeDriver(options);

ChromeOptions options = new ChromeOptions();

options.addArguments("--lang=" + "zh-CN");

WebDriver driver = new ChromeDriver(options);

// Windows下
ChromeOptions options = new ChromeOptions();

options.addArguments("user-data-dir=C:/Users/user_name/AppData/Local/Google/Chrome/User Data");

WebDriver driver = new ChromeDriver(options);

ChromeOptions options = new ChromeOptions();

options.addArguments("--test-type", "--ignore-certificate-errors");  
WebDriver driver = new ChromeDriver(options);

//Or Set chrome browser's capabilities to to accept SSL certificate on runtime. 
DesiredCapabilities capability = DesiredCapabilities.chrome(); 
capability.setCapability(CapabilityType.ACCEPT_SSL_CERTS, true); 
WebDriver driver = new ChromeDriver(capability);

ChromeOptions options = new ChromeOptions();

DesiredCapabilities capabilities = DesiredCapabilities.chrome();

capabilities.setCapability("chrome.switches", Arrays.asList("--start-maximized"));

options.addArguments("--test-type", "--start-maximized");
WebDriver driver = new ChromeDriver(options);