com.helger.datetime.config.PDTConfig.java Source code

Introduction

Here is the source code for com.helger.datetime.config.PDTConfig.java

Source

/**
 * Copyright (C) 2014-2015 Philip Helger (www.helger.com)
 * philip[at]helger[dot]com
 *
 * 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.
 */
package com.helger.datetime.config;

import java.util.TimeZone;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import javax.annotation.Nonnull;
import javax.annotation.concurrent.GuardedBy;
import javax.annotation.concurrent.ThreadSafe;

import org.joda.time.Chronology;
import org.joda.time.DateTimeZone;
import org.joda.time.chrono.GJChronology;
import org.joda.time.chrono.ISOChronology;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.helger.commons.ValueEnforcer;
import com.helger.commons.annotations.Nonempty;
import com.helger.commons.annotations.PresentForCodeCoverage;
import com.helger.commons.state.ESuccess;
import com.helger.datetime.PDTFactory;

/**
 * This class provides the most basic settings for date time operating: the
 * date-time-zone and the chronology to use.
 *
 * @author Philip Helger
 */
@ThreadSafe
public final class PDTConfig {
    /**
     * The default-default date time zone.
     */
    public static final String DEFAULT_DATETIMEZONEID = "Europe/Vienna";
    public static final boolean DEFAULT_USE_ISO_CHRONOLOGY = true;

    private static final Logger s_aLogger = LoggerFactory.getLogger(PDTConfig.class);
    private static final ReadWriteLock s_aRWLock = new ReentrantReadWriteLock();
    @GuardedBy("s_aRWLock")
    private static DateTimeZone s_aDefaultDateTimeZone;
    @GuardedBy("s_aRWLock")
    private static volatile boolean s_bUseISOChronology = DEFAULT_USE_ISO_CHRONOLOGY;

    static {
        // Ensure the JDK timezone is aligned to our default
        setDefaultDateTimeZoneID(DEFAULT_DATETIMEZONEID);
    }

    @PresentForCodeCoverage
    private static final PDTConfig s_aInstance = new PDTConfig();

    private PDTConfig() {
    }

    /**
     * Set the default date time zone to use. This effects all objects created via
     * {@link PDTFactory} as well as the default JDK TimeZone.
     *
     * @param sDateTimeZoneID
     *        Must be a valid, non-<code>null</code> time zone.
     * @return {@link ESuccess}
     */
    @Nonnull
    public static ESuccess setDefaultDateTimeZoneID(@Nonnull @Nonempty final String sDateTimeZoneID) {
        ValueEnforcer.notEmpty(sDateTimeZoneID, "DateTimeZoneID");

        s_aRWLock.writeLock().lock();
        try {
            // Try to resolve ID -> throws IAE if unknown
            s_aDefaultDateTimeZone = DateTimeZone.forID(sDateTimeZoneID);
            // getTimeZone falls back to GMT if unknown
            final TimeZone aDefaultTimeZone = TimeZone.getTimeZone(sDateTimeZoneID);
            TimeZone.setDefault(aDefaultTimeZone);
            return ESuccess.SUCCESS;
        } catch (final IllegalArgumentException ex) {
            // time zone ID is unknown
            s_aLogger.warn("Unsupported dateTimeZone ID '" + sDateTimeZoneID + "'");
            return ESuccess.FAILURE;
        } finally {
            s_aRWLock.writeLock().unlock();
        }
    }

    /**
     * @return The default date time zone to use. Never <code>null</code>. The
     *         default is {@link #DEFAULT_DATETIMEZONEID}.
     */
    @Nonnull
    public static DateTimeZone getDefaultDateTimeZone() {
        s_aRWLock.readLock().lock();
        try {
            return s_aDefaultDateTimeZone;
        } finally {
            s_aRWLock.readLock().unlock();
        }
    }

    /**
     * @return The default UTC date time zone. Never <code>null</code>.
     */
    @Nonnull
    public static DateTimeZone getDateTimeZoneUTC() {
        return DateTimeZone.UTC;
    }

    /**
     * @return <code>true</code> if {@link ISOChronology} should be used by
     *         default. Defaults to {@value #DEFAULT_USE_ISO_CHRONOLOGY}.
     */
    public static boolean isUseISOChronology() {
        s_aRWLock.readLock().lock();
        try {
            return s_bUseISOChronology;
        } finally {
            s_aRWLock.readLock().unlock();
        }
    }

    /**
     * Change whether ISO chronology should be used by default or
     * {@link GJChronology}.
     *
     * @param bUse
     *        <code>true</code> to use {@link ISOChronology}, <code>false</code>
     *        to use {@link GJChronology}.
     */
    public static void setUseISOChronology(final boolean bUse) {
        s_aRWLock.writeLock().lock();
        try {
            s_bUseISOChronology = bUse;
        } finally {
            s_aRWLock.writeLock().unlock();
        }
    }

    /**
     * @return The default chronology ({@link ISOChronology} or
     *         {@link GJChronology}) using the result of
     *         {@link #getDefaultDateTimeZone()}
     * @see #isUseISOChronology()
     * @see #getDefaultDateTimeZone()
     */
    @Nonnull
    public static Chronology getDefaultChronology() {
        if (isUseISOChronology())
            return ISOChronology.getInstance(getDefaultDateTimeZone());
        return GJChronology.getInstance(getDefaultDateTimeZone());
    }

    /**
     * @return The default chronology ({@link ISOChronology} or
     *         {@link GJChronology}) with UTC date time zone. Never
     *         <code>null</code>.
     * @see #isUseISOChronology()
     */
    @Nonnull
    public static Chronology getDefaultChronologyUTC() {
        if (isUseISOChronology())
            return ISOChronology.getInstanceUTC();
        return GJChronology.getInstanceUTC();
    }

    /**
     * @return The default chronology ({@link ISOChronology} or
     *         {@link GJChronology}) with the system date time zone. Never
     *         <code>null</code>.
     * @see #isUseISOChronology()
     */
    @Nonnull
    public static Chronology getDefaultChronologyWithDefaultDateTimeZone() {
        if (isUseISOChronology())
            return ISOChronology.getInstance();
        return GJChronology.getInstance();
    }
}