TimeProvider.java
- /*
- * *************************************************************************************************************************************************************
- *
- * TheseFoolishThings: Miscellaneous utilities
- * http://tidalwave.it/projects/thesefoolishthings
- *
- * Copyright (C) 2009 - 2025 by Tidalwave s.a.s. (http://tidalwave.it)
- *
- * *************************************************************************************************************************************************************
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
- * CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
- *
- * *************************************************************************************************************************************************************
- *
- * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
- * git clone https://github.com/tidalwave-it/thesefoolishthings-src
- *
- * *************************************************************************************************************************************************************
- */
- package it.tidalwave.util;
- import javax.annotation.Nonnull;
- import java.time.Instant;
- import java.time.LocalDateTime;
- import java.time.ZoneId;
- import java.time.ZonedDateTime;
- import java.util.concurrent.atomic.AtomicReference;
- import java.util.function.Supplier;
- /***************************************************************************************************************************************************************
- *
- * A provider of current time. It should be used by code requiring a timestamp, so it can be mocked during tests.
- * {@code MockTimeProvider} in module "Test Utilities" is a suitable mock for performing tests.
- *
- * @author Fabrizio Giudici
- * @since 3.2-ALPHA-1 (was previously InstantProvider since 1.39)
- *
- **************************************************************************************************************************************************************/
- @FunctionalInterface
- public interface TimeProvider extends Supplier<Instant>
- {
- // FIXME: should be private
- public static AtomicReference<TimeProvider> __INSTANCE = new AtomicReference<>();
- /***********************************************************************************************************************************************************
- * Returns the current time.
- *
- * @return the current time as an {@link Instant}
- * @since 3.2-ALPHA-2
- **********************************************************************************************************************************************************/
- @Nonnull
- public Instant currentInstant();
- /***********************************************************************************************************************************************************
- * Returns the current time. This method is provided to implement {@link Supplier}{@code <Instant>}.
- *
- * @return the current time as an {@link Instant}
- * @since 3.2-ALPHA-2
- **********************************************************************************************************************************************************/
- @Override @Nonnull
- public default Instant get()
- {
- return currentInstant();
- }
- /***********************************************************************************************************************************************************
- * Returns the current time.
- *
- * @return the current time as a {@link ZonedDateTime} in the default zone.
- * @since 3.2-ALPHA-2
- **********************************************************************************************************************************************************/
- @Nonnull
- public default ZonedDateTime currentZonedDateTime()
- {
- return ZonedDateTime.ofInstant(currentInstant(), ZoneId.systemDefault());
- }
- /***********************************************************************************************************************************************************
- * Returns the current time.
- *
- * @return the current time as a {@link LocalDateTime} in the default zone.
- * @since 3.2-ALPHA-2
- **********************************************************************************************************************************************************/
- @Nonnull
- public default LocalDateTime currentLocalDateTime()
- {
- return LocalDateTime.ofInstant(currentInstant(), ZoneId.systemDefault());
- }
- /***********************************************************************************************************************************************************
- * Returns the default instance.
- *
- * @return the default instance
- * @since 3.2-ALPHA-2
- **********************************************************************************************************************************************************/
- @Nonnull
- public static TimeProvider getInstance()
- {
- synchronized (TimeProvider.class)
- {
- if (__INSTANCE.get() == null)
- {
- __INSTANCE.set(new DefaultTimeProvider());
- }
- return __INSTANCE.get();
- }
- }
- /***********************************************************************************************************************************************************
- *
- **********************************************************************************************************************************************************/
- static class DefaultTimeProvider implements TimeProvider
- {
- @Override @Nonnull
- public Instant currentInstant()
- {
- return Instant.now();
- }
- }
- }