How to use getLogLevel method of org.openqa.selenium.chrome.ChromeOptions class

Instead of class name you can use a css selector. You don't mention the tagname for the class 'current time'. I am assuming it to be input, so your css selector work be,

WebElement element = driver.findElement(By.cssSelector("input[class='current time']"));
element.click();

Edit#1 Based on html provided,

Looking at the html in your comment, it seems you have quite a few options to find the webElement. Here are your options,

WebElement element = driver.findElement(By.cssSelector("a[class='current time']"));
element.click();

or this should work too,

WebElement element = driver.findElement(By.cssSelector("a.current.time"));
element.click();

You can also use linkText since the element is link. From the html you provided, the link text is 'url'

WebElement element = driver.findElement(By.linkText("url"));
element.click();

You can also use By.partialLinkText("partial link text here");

You can also use xpath as:

WebElement element = driver.findElement(By.xpath("//a[@class='current time']"));
element.click();

OR,

WebElement element = driver.findElement(By.xpath("//a[text() = 'url']"));
element.click();

After digging a little deeper, I came to the following findings which eventually solved my issue:

1. Marionette resp. wires uses two ports (see wires --help); a marionette-port and a webdriver-port:

   Usage:
       ./wires [OPTIONS]
   
   WebDriver to marionette proxy.
   
   optional arguments:
     -h,--help             show this help message and exit
     -b,--binary BINARY    Path to the Firefox binary
     --webdriver-host WEBDRIVER_HOST
                           Host to run webdriver server on
     --webdriver-port WEBDRIVER_PORT
                           Port to run webdriver on
     --marionette-port MARIONETTE_PORT
                           Port to run marionette on
     --connect-existing    Connect to an existing firefox process
   

   When running multiple MarionetteDrivers simultaneously, both ports have to be different from the already running instance obviously. However, when using the default constructor new MarionetteDriver() the marionette-port remains constant (and is not determined based on some free port). We used some workaround (see below) for the GeckoDriverService.Builder to always pick two randomly-chosen available ports.

2. The current (version 2.48.2) GeckoDriverService has an empty implementation of waitUntilAvailable() (which should check, if the WebDriver is ready to go). Sporadically, this lead to the UnreachableBrowserException posted above.

To circumvent these issues, we did something like this at the end:

// determine free ports for Marionette and WebDriver
final int marionettePort = PortProber.findFreePort();
final int webDriverPort = PortProber.findFreePort();
// override, as GeckoDriverService provides no direct way to set the Marionette port
GeckoDriverService.Builder builder = new GeckoDriverService.Builder() {
    @Override
    protected ImmutableList<String> createArgs() {
        Builder<String> argsBuilder = ImmutableList.builder();
        argsBuilder.addAll(super.createArgs());
        argsBuilder.add(String.format("--marionette-port=%d", marionettePort));
        return argsBuilder.build();
    }
};
builder.usingPort(webDriverPort);
builder.usingDriverExecutable(pathToDriver);
GeckoDriverService driverService = builder.build();
try {
    driverService.start();
} catch (IOException e) {
    throw new IllegalStateException("Could not start the GeckoDriverService", e);
}
try {
    // keep checking the WebDriver port via Socket until it's available;
    // as far as I could tell, there is nothing more "high level", e.g. REST API
    waitUntilReady(webDriverPort, TimeUnit.SECONDS.toMillis(30));
} catch (InterruptedException e) {
    // ignore
}
return new MarionetteDriver(driverService, capabilities);

You can perform any action on driver object, if it is throwing UnreachableBrowserException, then there is problem to communicate with the browser.

The most common causes for this exception are:

1. The provided server address to RemoteWebDriver is invalid, so the connection could not be established.
2. The browser has died mid-test.

And you can call the following method to verify the browser is closed or not.

public boolean isBrowserClosed(WebDriver driver)
{
    boolean isClosed = false;
    try {
        driver.getTitle();
    } catch(UnreachableBrowserException ubex) {
        isClosed = true;
    }

    return isClosed;
}

According to Ashley Wilson's report from sauce labs:

Pros:

1. They’re faster
2. They’re more readable
3. CSS is jQuery’s locating strategy
4. No one else uses XPATH anyways!

It's a bit outdated, however here are the numbers:

Personally, I would argue about (2)-nd statement, I must agree with the rest.

Cons:

1. No "bottom up" navigation. XPath has elem\..\another_elem
2. Is Sizzle injected? Or Browser's CSS locator parser is used? Depends on the browser, and there are inconsistencies.

The type command may not be enough to trigger the autocomplete. Dave Webb's suggestions are otherwise spot on. My only addition would be that you might need the typeKeys command, which causes slightly different JavaScript events to be fired, which may be more likely to trigger the autocomplete widget.

If you want to scroll on the firefox window using selenium webdriver, one of the way is to use javaScript in the java code, The javeScript code to scroll down is as follows:

WebDriver driver = new FirefoxDriver();
JavascriptExecutor js = (JavascriptExecutor)driver;
js.executeScript("window.scrollTo(0,Math.max(document.documentElement.scrollHeight," + "document.body.scrollHeight,document.documentElement.clientHeight));");

You are using javascript that scrolls the main window, if you want to scroll a element, you should first get the element by id, then change the its scrollLeft property:

JavascriptExecutor js = (JavascriptExecutor)driver; 
js.executeScript(
    "document.getElementById('gvLocationHorizontalRail').scrollLeft += 250", "");

If you instead want to change the scrollbar that moves up and down, you should change the scrollTop property.

In Selenium 4 alpha, there is a way to interact with DevTools API using the java-client. What you are looking for specifically is the "Profiler" domain (https://chromedevtools.github.io/devtools-protocol/tot/Profiler)

Recently, I contributed the "Network" and "Performance" domains for a better user facing API in selenium java - https://github.com/SeleniumHQ/selenium/pull/7212

I believe that "Profiler" will also be implemented soon. Of course, there is a generic API for all domains in Java client that was merged a while ago, you can use it like this:

     driver.getDevTools().createSession();

    driver.getDevTools().send(new Command("Profiler.enable", ImmutableMap.of()));
    driver.getDevTools().send(new Command("Profiler.start", ImmutableMap.of()));

    //register to profiler events
    driver.getDevTools().addListener(new Event("Profiler.consoleProfileStarted", ConsoleProfileStarted.class), new Consumer<Object>() {
        @Override
        public void accept(Object o) {
            //do something
        }
    });

Until the Profiler domain will added to Selenium java client, you will have to supply your Mapper.

This is the telemetry feature, and the prompt is controlled by the toolkit.telemetry.prompted property:

https://wiki.mozilla.org/Security/Reviews/Firefox6/ReviewNotes/telemetry

You can set it via prefs.js:

http://kb.mozillazine.org/Prefs.js_file

Also relevant:

http://code.google.com/p/selenium/issues/detail?id=3144