Java Millisecond Format createDateTimeString(final long ms, final DateFormat timeFormat, final String milliSep)

Description

Creates a string from a date given the appropriate time format and millisecond separator.

License

Apache License

Parameter

Parameter	Description
ms	The date to use.
timeFormat	The time format to use for the time part.
milliSep	The separator to place before the milliseconds.

Return

A string representation of the supplied date.

Declaration

private static String createDateTimeString(final long ms, final DateFormat timeFormat, final String milliSep) 

Method Source Code

//package com.java2s;
/*//from  ww w  .j av  a2s.  c  om
 * Copyright 2016 Crown Copyright
 *
 * 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.
 */

import java.text.DateFormat;

import java.text.SimpleDateFormat;
import java.util.Arrays;

import java.util.Date;

import java.util.TimeZone;

public class Main {
    private static final TimeZone UTC_TIME_ZONE = TimeZone.getTimeZone("+0000");
    private static final String DATE_FORMAT = "yyyy-MM-dd";
    private static final String TIME_SEPERATOR = "T";
    private static final String TIME_ZONE = "Z";
    private static final int MS_IN_SEC = 1000;
    private static final int THREE = 3;

    /**
     * Creates a string from a date given the appropriate time format and millisecond separator.
     * 
     * @param ms
     *            The date to use.
     * @param timeFormat
     *            The time format to use for the time part.
     * @param milliSep
     *            The separator to place before the milliseconds.
     * @return A string representation of the supplied date.
     */
    private static String createDateTimeString(final long ms, final DateFormat timeFormat, final String milliSep) {
        final long seconds = ms / MS_IN_SEC;
        final long fraction = ms - seconds * MS_IN_SEC;

        String millis = Long.toString(fraction);
        millis = leftPad(millis, THREE, '0');

        final SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
        sdf.setTimeZone(UTC_TIME_ZONE);

        final Date date = new Date(ms);
        final StringBuilder builder = new StringBuilder(128);
        builder.append(sdf.format(date));
        builder.append(TIME_SEPERATOR);
        builder.append(timeFormat.format(date));
        builder.append(milliSep);
        builder.append(millis);
        builder.append(TIME_ZONE);

        return builder.toString();
    }

    /**
     * Utility method for padding a string to a certain number of characters. Characters are appended to the left hand
     * side of the string to make it the specified length. IF the string is already longer than the specified length is
     * is just returned and not truncated.
     * 
     * @param str
     *            The string to pad.
     * @param size
     *            The required padded size of the string.
     * @param padChar
     *            The character to pad the string with.
     * @return The padded string.
     */
    public static String leftPad(final String str, final int size, final char padChar) {
        final int len = str.length();
        if (len >= size) {
            return str;
        }

        final char[] padding = new char[size];
        Arrays.fill(padding, 0, size - len, padChar);
        str.getChars(0, len, padding, size - len);
        return new String(padding).toString();
    }
}

Related

1. format(final long timeInMillis)
2. format(long millis)
3. format(long millis)
4. format(long millis)