Speed up JUnit tests by running them in parallel

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.junit.runners.Parameterized;
import org.junit.runners.model.RunnerScheduler;

public class Parallelized extends Parameterized {

	private static class ThreadPoolScheduler implements RunnerScheduler {
		private ExecutorService executor;

		public ThreadPoolScheduler() {
			String threads = System.getProperty("junit.parallel.threads", "16");
			int numThreads = Integer.parseInt(threads);
			executor = Executors.newFixedThreadPool(numThreads);
		}

		@Override
		public void finished() {
			executor.shutdown();
			try {
				executor.awaitTermination(10, TimeUnit.MINUTES);
			} catch (InterruptedException exc) {
				throw new RuntimeException(exc);
			}
		}

		@Override
		public void schedule(Runnable childStatement) {
			executor.submit(childStatement);
		}
	}

	public Parallelized(Class<?> klass) throws Throwable {
		super(klass);
		setScheduler(new ThreadPoolScheduler());
	}
}

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.LinkedList;

import org.apache.commons.io.FileUtils;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.openqa.selenium.By;
import org.openqa.selenium.OutputType;
import org.openqa.selenium.Platform;
import org.openqa.selenium.TakesScreenshot;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.remote.Augmenter;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.remote.RemoteWebDriver;

@RunWith(Parallelized.class)
public class JUnitParallel {
	private String platform;
	private String browserName;
	private String browserVersion;

	@Parameterized.Parameters
	public static LinkedList<String[]> getEnvironments() throws Exception {
		LinkedList<String[]> env = new LinkedList<String[]>();
		env.add(new String[]{Platform.WINDOWS.toString(), "chrome", "latest"});
		env.add(new String[]{Platform.WINDOWS.toString(),"firefox","latest"});
		env.add(new String[]{Platform.WINDOWS.toString(),"ie","9"});

		//add more browsers here

		return env;
	}


	public JUnitParallel(String platform, String browserName, String browserVersion) {
		this.platform = platform;
		this.browserName = browserName;
		this.browserVersion = browserVersion;
	}

	private WebDriver driver;

	@Before
	public void setUp() throws Exception {
		DesiredCapabilities capability = new DesiredCapabilities();
		capabilities.setCapability(CapabilityType.BROWSER_NAME, browserName);
		capabilities.setCapability(CapabilityType.BROWSER_VERSION, browserVersion);
		capabilities.setCapability(CapabilityType.PLATFORM_NAME, platform);
		Map<String, Object> testingBotOptions = new HashMap<>();
		testingBotOptions.put("name", "Parallel test");
		capabilities.setCapability("tb:options", testingBotOptions);

		driver = new RemoteWebDriver(
			new URL("https://key:secret@hub.testingbot.com/wd/hub"),
			capability
		);
	}

	@Test
	public void testSimple() throws Exception {
		driver.get("https://www.google.com");
		String title = driver.getTitle();
		System.out.println("Page title is: " + title);
		driver = new Augmenter().augment(driver);
		File srcFile = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
		try {
			FileUtils.copyFile(srcFile, new File("Screenshot.png"));
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	@After
	public void tearDown() throws Exception {
		driver.quit();
	}
}

java -jar testingbot-tunnel.jar key secret

@Before
public void setUp() throws Exception {
	DesiredCapabilities capability = new DesiredCapabilities();
	capabilities.setCapability(CapabilityType.BROWSER_NAME, browserName);
	capabilities.setCapability(CapabilityType.BROWSER_VERSION, browserVersion);
	capabilities.setCapability(CapabilityType.PLATFORM_NAME, platform);
	Map<String, Object> testingBotOptions = new HashMap<>();
	testingBotOptions.put("name", "Parallel test");
	capabilities.setCapability("tb:options", testingBotOptions);
	driver = new RemoteWebDriver(
		new URL("http://key:secret@localhost:4445/wd/hub"),
		capability
	);
}

import com.testingbot.testingbotrest.TestingbotREST;

@After
public void tearDown() throws Exception {
	TestingbotREST r = new TestingbotREST("key", "secret");
	Map<String, String> data = new HashMap<String, String>();
	data.put("success", "1");
	data.put("name", "My Test");
	r.updateTest(driver.getSessionId(), data);
	driver.quit();
}