Java Clock.fixed

Service.java

  @Named
  public class Service(){
    Clock clock;
    public Service(Clock clock){
      this.clock = clock;
    } 
    public void work(){
      System.Out.plintln("time:" + Instant.now(clock));
    }
  }

UseClock.java

    Clock clock = Clock.fixed(Instant.parse("2015-01-01T00:00:00Z"), ZoneId.systemDefault());
    Service service;
    @Before
    public void before(){
      service = new Service(clock);
    }
    
    @Test
    public void test(){
      service.work(); // shown 2015-01.
    }