ISO8601 DateFormat

DateUtils.java

/*
 * Copyright 2015 Blue Lotus Software, LLC.
 *
 * 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.bluelotussoftware.jsf.utils;

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

/**
 * A collection of utilities to handle common date conversions.
 *
 * @author John Yeary <[email protected]>
 * @version 1.0
 */
public final class DateUtils {

    private static final ThreadLocal<DateFormat> iso8601DateFormatter = new ThreadLocal<DateFormat>() {

        @Override
        public DateFormat get() {
            return super.get();
        }

        @Override
        protected DateFormat initialValue() {
            DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.US);
            dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
            return dateFormat;
        }

        @Override
        public void remove() {
            super.remove();
        }

        @Override
        public void set(DateFormat value) {
            super.set(value);
        }

    };

    /**
     * <p>
     * Convert a {@link Date} to an ISO 8601 combined date and time string.</p>
     * <p>
     * <strong>Note:</strong> This method is thread-safe since it uses a
     * {@link ThreadLocal} version of the {@link DateFormat} class.
     *
     * @param date The {@link Date} to evaluate and convert.
     * @return {@code String} with format "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
     */
    public static String getISO8601Date(final Date date) {
        String formattedDate = iso8601DateFormatter.get().format(date);
        iso8601DateFormatter.remove();
        return formattedDate;
    }

}