org.junit.rules

Class Stopwatch

java.lang.Object

org.junit.rules.TestWatcher

org.junit.rules.Stopwatch

All Implemented Interfaces:

TestRule

public class Stopwatch
extends TestWatcher

The Stopwatch Rule notifies one of its own protected methods of the time spent by a test.

Override them to get the time in nanoseconds. For example, this class will keep logging the time spent by each passed, failed, skipped, and finished test:

 public static class StopwatchTest {
     private static final Logger logger= Logger.getLogger("");

     private static void logInfo(String testName, String status, long nanos) {
         logger.info(String.format("Test %s %s, spent %d microseconds",
                                     testName, status, Stopwatch.toMicros(nanos)));
     }

     @Rule
     public Stopwatch stopwatch= new Stopwatch() {
         @Override
         protected void succeeded(long nanos, Description description) {
             logInfo(description.getMethodName(), "succeeded", nanos);
         }

         @Override
         protected void failed(long nanos, Throwable e, Description description) {
             logInfo(description.getMethodName(), "failed", nanos);
         }

         @Override
         protected void skipped(long nanos, AssumptionViolatedException e, Description description) {
             logInfo(description.getMethodName(), "skipped", nanos);
         }

         @Override
         protected void finished(long nanos, Description description) {
             logInfo(description.getMethodName(), "finished", nanos);
         }
     };

     @Test
     public void succeeds() {
     }

     @Test
     public void fails() {
         fail();
     }

     @Test
     public void skips() {
         assumeTrue(false);
     }
 }
 

An example to assert runtime:

 @Test
 public void performanceTest() throws InterruptedException {
     long delta= 30;
     Thread.sleep(300L);
     assertEquals(300d, stopwatch.runtime(MILLISECONDS), delta);
     Thread.sleep(500L);
     assertEquals(800d, stopwatch.runtime(MILLISECONDS), delta);
 }
 

Since:

4.12

Constructor Summary

Constructors

Constructor and Description
Stopwatch()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	failed(long nanos, Throwable e, Description description) Invoked when a test fails
protected void	failed(Throwable e, Description description) Invoked when a test fails
protected void	finished(Description description) Invoked when a test method finishes (whether passing or failing)
protected void	finished(long nanos, Description description) Invoked when a test method finishes (whether passing or failing)
long	runtime(TimeUnit unit)
protected void	skipped(org.junit.internal.AssumptionViolatedException e, Description description) Invoked when a test is skipped due to a failed assumption.
protected void	skipped(long nanos, org.junit.internal.AssumptionViolatedException e, Description description) Invoked when a test is skipped due to a failed assumption.
protected void	starting(Description description) Invoked when a test is about to start
protected void	succeeded(Description description) Invoked when a test succeeds
protected void	succeeded(long nanos, Description description) Invoked when a test succeeds
static long	toMicros(long nanos)
static long	toMillis(long nanos)
static long	toSeconds(long nanos)

Methods inherited from class org.junit.rules.TestWatcher

apply

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Stopwatch

public Stopwatch()

Method Detail

runtime

public long runtime(TimeUnit unit)

Parameters:

unit - time unit for returned runtime

Returns:

runtime measured during the test

succeeded

protected void succeeded(long nanos,
             Description description)

Invoked when a test succeeds

failed

protected void failed(long nanos,
          Throwable e,
          Description description)

Invoked when a test fails

skipped

protected void skipped(long nanos,
           org.junit.internal.AssumptionViolatedException e,
           Description description)

Invoked when a test is skipped due to a failed assumption.

finished

protected void finished(long nanos,
            Description description)

Invoked when a test method finishes (whether passing or failing)

toMicros

public static long toMicros(long nanos)

Parameters:

nanos - time in nanoseconds

Returns:

time converted to microseconds

toMillis

public static long toMillis(long nanos)

Parameters:

nanos - time in nanoseconds

Returns:

time converted to milliseconds

toSeconds

public static long toSeconds(long nanos)

Parameters:

nanos - time in nanoseconds

Returns:

time converted to seconds

succeeded

protected final void succeeded(Description description)

Description copied from class: TestWatcher

Invoked when a test succeeds

Overrides:

succeeded in class TestWatcher

failed

protected final void failed(Throwable e,
          Description description)

Description copied from class: TestWatcher

Invoked when a test fails

Overrides:

failed in class TestWatcher

skipped

protected final void skipped(org.junit.internal.AssumptionViolatedException e,
           Description description)

Description copied from class: TestWatcher

Invoked when a test is skipped due to a failed assumption.

Overrides:

skipped in class TestWatcher

starting

protected final void starting(Description description)

Description copied from class: TestWatcher

Invoked when a test is about to start

Overrides:

starting in class TestWatcher

finished

protected final void finished(Description description)

Description copied from class: TestWatcher

Invoked when a test method finishes (whether passing or failing)

Overrides:

finished in class TestWatcher