cal.java

Calendar rightNow = Calendar.getInstance();

OnlineStatus.java

public class OnlineStatus {
    public enum States {Unknown, Online}

    private int onlineThresholdHrs;

    public void setOnlineThresholdHrs(int hours) {
        this.onlineThresholdHrs = hours;
    }

    public States getStatus(Date lastOnline, Calendar calendar) {
        int currentHour = calendar.get(Calendar.HOUR_OF_DAY);
        calendar.set(
                Calendar.HOUR_OF_DAY,
                currentHour + onlineThresholdHrs);

        Date onlineThreshold = calendar.getTime();
        if (lastOnline.before(onlineThreshold)) {
            return States.Online;
        } else {
            return States.Unknown;
        }
    }
}

OnlineTest.java

@Test
public void onlineTest() throws Exception {
    Profile profile = new Profile();
    //sets instance to right now
    Calendar calendar = Calendar.getInstance();

    //get time of right now and set users online status with it
    profile.setLastOnline(calendar.getTime());

    //create and configure
    OnlineStatus onlineStatus = new OnlineStatus();
    onlineStatus.setOnlineThresholdHrs(1);

    OnlineStatus.States status = onlineStatus.getStatus(
            profile.getLastOnline(),
            calendar
    );
    assertEquals(status, OnlineStatus.States.Online);
}

profile-model.java

public class Profile {
  Date lastOnline;
  public Date getLastOnline() {
      return lastOnline;
  }

  public void setLastOnline(Date lastOnline) {
      this.lastOnline = lastOnline;
  }
}