net.naonedbus.provider.impl.FastDateTimeZoneProvider.java Source code

Introduction

Here is the source code for net.naonedbus.provider.impl.FastDateTimeZoneProvider.java

Source

/**
 * Copyright (C) 2013 Romain Guefveneu.
 *   
 *  This file is part of naonedbus.
 *   
 *  Naonedbus is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *  
 *  Naonedbus is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package net.naonedbus.provider.impl;

import java.util.Arrays;
import java.util.Date;
import java.util.HashSet;
import java.util.Set;
import java.util.TimeZone;

import org.joda.time.DateTimeZone;
import org.joda.time.tz.Provider;

/**
 * @author romain.guefveneu
 * 
 */
public class FastDateTimeZoneProvider implements Provider {
    public static final Set<String> AVAILABLE_IDS = new HashSet<String>();

    static {
        AVAILABLE_IDS.addAll(Arrays.asList(TimeZone.getAvailableIDs()));
    }

    public DateTimeZone getZone(String id) {
        if (id == null) {
            return DateTimeZone.UTC;
        }

        TimeZone tz = TimeZone.getTimeZone(id);
        if (tz == null) {
            return DateTimeZone.UTC;
        }

        int rawOffset = tz.getRawOffset();

        // sub-optimal. could be improved to only create a new Date every few
        // minutes
        if (tz.inDaylightTime(new Date())) {
            rawOffset += tz.getDSTSavings();
        }

        return DateTimeZone.forOffsetMillis(rawOffset);
    }

    public Set<String> getAvailableIDs() {
        return AVAILABLE_IDS;
    }
}