SystemTime.java

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 * Copyright (c) quickfixengine.org  All rights reserved.
 *
 * This file is part of the QuickFIX FIX Engine
 *
 * This file may be distributed under the terms of the quickfixengine.org
 * license as defined by quickfixengine.org and appearing in the file
 * LICENSE included in the packaging of this file.
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING
 * THE WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE.
 *
 * See http://www.quickfixengine.org/LICENSE for licensing information.
 *
 * Contact ask@quickfixengine.org if any conditions of this licensing
 * are not clear to you.
 ******************************************************************************/

package quickfix;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

/**
 * A wrapper for the system time source, used primarily for unit testing.
 */
public class SystemTime {
    public static final TimeZone UTC_TIMEZONE = TimeZone.getTimeZone("UTC");

    private static final SystemTimeSource DEFAULT_TIME_SOURCE = new SystemTimeSource() {
        @Override
        public long getTime() {
            return System.currentTimeMillis();
        }

        @Override
        public long getTimeFromNanos() {
            return System.nanoTime();
        }

        @Override
        public LocalDateTime getNow() {
            return LocalDateTime.now(ZoneOffset.UTC);
        }
    };

    private static volatile SystemTimeSource systemTimeSource = DEFAULT_TIME_SOURCE;

    public static long currentTimeMillis() {
        return systemTimeSource.getTime();
    }

    public static long currentTimeMillisFromNanos() {
        return systemTimeSource.getTimeFromNanos();
    }
    
    public static LocalDateTime now() {
        return systemTimeSource.getNow();
    }

    public static Date getDate() {
        return new Date(currentTimeMillis());
    }

    public static LocalDateTime getLocalDateTime() {
        return now();
    }

    public static void setTimeSource(SystemTimeSource systemTimeSource) {
        SystemTime.systemTimeSource = systemTimeSource != null ? systemTimeSource
                : DEFAULT_TIME_SOURCE;
    }

    public static Calendar getUtcCalendar() {
        Calendar c = Calendar.getInstance(SystemTime.UTC_TIMEZONE);
        c.setTimeInMillis(currentTimeMillis());
        return c;
    }

    public static Calendar getUtcCalendar(Date date) {
        Calendar c = getUtcCalendar();
        c.setTime(date);
        return c;
    }

    public static Calendar getUtcCalendar(long time) {
        Calendar c = getUtcCalendar();
        c.setTimeInMillis(time);
        return c;
    }

}