Package org.forgerock.util.time

Interface TimeService

public interface TimeService
Provides time related methods for computing durations, for providing the now instant and other use cases.

Why using a service interface instead of JVM provided time methods?

Simply because you gain better control over the time understood by the application. For example, if you would have to code an expiration time logic, you would check periodically if the computed expiration timestamp is greater than the now timestamp. So far, so good.

When it comes to testing, things gets worst: you typically have to use Thread.sleep(long) to wait for a given amount of time so that your expiration date is reached. That makes tests much longer to execute and somehow brittle when you're testing short timeouts.

Using a TimeService helps you to keep your code readable and provides a way to better control how the time is flowing for your application (especially useful in the tests).

For example, now() is used in place of System.currentTimeMillis(). in your code and you can easily mock it and make it return controlled values. Here is an example with Mockito: 

 @Mock
 private TimeService time;

 @BeforeMethod
 public void setUp() throws Exception {
     MockitoAnnotations.initMocks(this);
 }

 @Test
 public shouldAdvanceInTime() throws Exception {
     // Mimics steps in the future at each call
     when(time.now()).thenReturn(0L, 1000L, 10000L);

     assertThat(time.now()).isEqualTo(0L);
     assertThat(time.now()).isEqualTo(1000L);
     assertThat(time.now()).isEqualTo(10000L);
 }
TimeService provides a default service implementation using the System provided time methods for ease of use.
Since:
1.3.4
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final TimeService
    SYSTEM
    TimeService implementation based on System.

  • Method Summary

    Modifier and Type
    Method
    Description
    long
    now()
    Returns a value that represents "now" since the epoch.
    long
    since(long past)
    Computes the elapsed time between now and past.

  • Field Details

  • Method Details

    • now

      long now()
      Returns a value that represents "now" since the epoch.
      Returns:
      a value that represents "now" since the epoch.
      Since:
      1.3.4

    • since

      long since(long past)
      Computes the elapsed time between now and past.
      Parameters:
      past - time value to compare to now.
      Returns:
      the elapsed time
      Since:
      1.3.4