RemoteWebDriver

Remote WebDriver

This is information about using the client implementation of the RemoteWebDriver. This is the code that is used within your tests. For information on how to set up the server-side, please take a look at the RemoteWebDriverServer page.

Installing

Download the "selenium-server.zip" and unpack. Put the JARs on the CLASSPATH. This will give you the remote webdriver client, which is generally what you need. Please consult the RemoteWebDriverServer for information on how to set up the server-side of the remote webdriver.

Pros

Separates where the tests are running from where the browser is.
Allows tests to be run with browsers not available on the current OS (because the browser can be elsewhere)

Cons

Requires an external servlet container to be running
You may find problems with line endings when getting text from the remote server
Introduces extra latency to tests, particularly when exceptions are thrown.

Using

This is probably best demonstrated with some code:

// We could use any driver for our tests...
DesiredCapabilities capabilities = new DesiredCapabilities();

// ... but only if it supports javascript
capabilities.setJavascriptEnabled(true);

// Get a handle to the driver. This will throw an exception
// if a matching driver cannot be located
WebDriver driver = new RemoteWebDriver(capabilities);

// Query the driver to find out more information
Capabilities actualCapabilities = ((RemoteWebDriver) driver).getCapabilities();

// And now use it
driver.get("http://www.google.com");

One nice feature of the remote webdriver is that exceptions often have an attached screen shot, encoded as a Base64 PNG. In order to get this screenshot, you need to write code similar to:

public String extractScreenShot(WebDriverException e) {
  Throwable cause = e.getCause();
  if (cause instanceof ScreenshotException) {
    return ((ScreenshotException) cause).getBase64EncodedScreenshot();
  }
  return null;
}