Junit4 running parallel junit classes

To run junit testcases parallel, you can create your own class to run junit with:

Add this tag to your class declaration.

@RunWith(Parallelized.class)

Implementation of this class looks like:

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

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

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

Now inside your test class, you will need to create a method with

@Parameters

tag declaration, that feeds the constructor:

    public PocAddPoiTest(String browser) {
        super();
        this.browser = browser;
    }

    @Parameters
    public static Collection browsersStrings() {
        // return Arrays.asList(new Object[][] { { "*firefox" },
        // { "*googlechrome" } });
        return Arrays.asList(new Object[][] { { "*firefox","*iexplore" } });
    }

When junit gets started, it will run two tests parallel.

Not sure how it handles output .. :-).