An example of using junit-4-perfrunner for performance testing in java. The code graphs the results. Further explanation can be seen at www.petramoessner.blogspot.com.

Using junit-4-perfrunner

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.jboss.perfrunner.Axis;
import org.jboss.perfrunner.PerfRunner;
import org.jboss.perfrunner.Varying;
import org.junit.Test;
import org.junit.runner.RunWith;

@RunWith(PerfRunner.class)       
public class SampleTest {
  

  @Test  
	public void numTest (
	@Varying(name = "MB", axis=Axis.X, from = 1, to = 10000000,step = 250000)int numMax)throws Exception{
	
		String content = "0";     
		FileWriter fstream = new FileWriter("out.txt");    
		BufferedWriter out = new BufferedWriter(fstream);
		for(int num=0; num < numMax; num++){   
    
	  	out.write(content);
	  	}
		  out.close();
	  }

	 @Test

	 public void perThread
	 
	@Varying(name = "thread", axis = Axis.X, from = 1, to = 10, step = 1) final int threadCount) throws InterruptedException {
 
	 // First define the task that needs to be done.

	 // This task writes a million 'a' characters to a file:

	 Runnable task = new Runnable() {

	 @Override

	 public void run() {

  try{
			
      // create temporary file with extension suffix
		 File file1 = null;

	   file1 = File.createTempFile("PerThreadTest", ".javatemp");

	   BufferedWriter out = new BufferedWriter(new FileWriter(file1));

	   int megabyte = 1000000;

	   for (int i = 1; i < megabyte; i++) {

		    out.write('a');
	
	      }
        out.close() ;
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	
	 }

	 };
	  
	 // Now define the executor service that will execute the above task

	 ExecutorService exec = Executors.newFixedThreadPool(threadCount);

	 // Submit the task 10 times (total data written will be 10MB)

	 for (int i = 0; i < 10; i++) {

	 exec.submit(task);

	 }

	 // Finally, wait for all the submitted tasks to complete (1 hour should be way more than enough!)

	 exec.awaitTermination(1, TimeUnit.SECONDS);

	 // Free the threads that were created by Executors.newFixedThreadPool(threadCount) above

	 exec.shutdown();

	 }

  @Test
   public void perThread2 (
	 @Varying(axis=Axis.SERIES, name = "Megabyte",from = 10000000, to = 100000000, step= 10000000) final int megabyte,
	@Varying(name = "thread", axis = Axis.X, from = 1, to = 10, step = 1) final int threadCount) throws InterruptedException {
 
	 // First define the task that needs to be done.

	 Runnable task = new Runnable() {

	 @Override

	 public void run() {

  try{
			
      // create temporary file with extension suffix
		 File file1 = null;

	   file1 = File.createTempFile("PerThreadTest", ".javatemp");

	   BufferedWriter out = new BufferedWriter(new FileWriter(file1));

    	 for (int i = 1; i < megabyte; i++) {

		    out.write('a');
	
	       }
        out.close() ;
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	
	 }

	 };
	  
	 // Now define the executor service that will execute the above task

	 ExecutorService exec = Executors.newFixedThreadPool(threadCount);

	 // Submit the task 10 times 

	 for (int i = 0; i < 10; i++) {

	 exec.submit(task);

	 }

	 // Finally, wait for all the submitted tasks to complete (1 hour should be way more than enough!)

	 exec.awaitTermination(1, TimeUnit.SECONDS);

	 // Free the threads that were created by Executors.newFixedThreadPool(threadCount) above

	 exec.shutdown();   

	 }

}