SimpleDateFormatter.java

/*******************************************************************************
 *   Copyright (c) 2013 Steve Flasby
 *   All rights reserved.
 *   Redistribution and use in source and binary forms, with or without modification,
 *   are permitted provided that the following conditions are met:
 *   <ul>
 *       <li>Redistributions of source code must retain the above copyright notice,
 *           this list of conditions and the following disclaimer.</li>
 *       <li>Redistributions in binary form must reproduce the above copyright notice,
 *           this list of conditions and the following disclaimer in the documentation
 *           and/or other materials provided with the distribution.</li>
 *   </ul>
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 *   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *   IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 *   OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 *   ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *  
 *******************************************************************************/
package org.flasby.util;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

public class SimpleDateFormatter {
	final String format;
	final Locale locale;
    final TimeZone timeZone;

	private final ThreadLocal<SimpleDateFormat> sdf = new ThreadLocal<SimpleDateFormat>() {
		@Override
		protected SimpleDateFormat initialValue() {
			SimpleDateFormat gmtFrmt = (locale == null) ? 
					new java.text.SimpleDateFormat(format) : 
					new java.text.SimpleDateFormat(format, locale);
			if (timeZone != null) {
				gmtFrmt.setTimeZone(timeZone);
			}

			return gmtFrmt;
		}
	};

	public SimpleDateFormatter(String format, Locale locale, TimeZone timeZone) {
		this.format = format;
		this.locale = locale;
		if ( timeZone != null ) {
			this.timeZone = TimeZone.getTimeZone( timeZone.getID() );
		} else {
			this.timeZone = null;
		}
	}

	public SimpleDateFormatter(String format, Locale locale) {
		this(format, locale, null);
	}

	public SimpleDateFormatter(String format) {
		this(format, null, null);
	}

	public String format(Date date) {
		return sdf.get().format(date);
	}

}