    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.lang3.time;
    019
    020import java.util.Calendar;
    021import java.util.Locale;
    022import java.util.Map;
    023import java.util.Objects;
    024
    025/**
    026 * Helps use {@link Calendar}s.
    027 *
    028 * @since 3.10
    029 */
    030public class CalendarUtils {
    031
    032    /**
    033     * The singleton instance for {@link Calendar#getInstance()}.
    034     */
    035    public static final CalendarUtils INSTANCE = new CalendarUtils(Calendar.getInstance());
    036
    037    /**
    038     * Gets a CalendarUtils using the default time zone and specified locale. The <code>CalendarUtils</code> returned is based on the current time in the
    039     * default time zone with the given locale.
    040     *
    041     * @param locale the locale for the week data
    042     * @return a Calendar.
    043     */
    044    static CalendarUtils getInstance(final Locale locale) {
    045        return new CalendarUtils(Calendar.getInstance(locale), locale);
    046    }
    047
    048    private final Calendar calendar;
    049
    050    private final Locale locale;
    051
    052    /**
    053     * Creates an instance for the given Calendar.
    054     *
    055     * @param calendar A Calendar.
    056     */
    057    public CalendarUtils(final Calendar calendar) {
    058        this(calendar, Locale.getDefault());
    059    }
    060
    061    /**
    062     * Creates an instance for the given Calendar.
    063     *
    064     * @param calendar A Calendar.
    065     * @param locale A Locale.
    066     */
    067    CalendarUtils(final Calendar calendar, final Locale locale) {
    068        this.calendar = Objects.requireNonNull(calendar, "calendar");
    069        this.locale = Objects.requireNonNull(locale, "locale");
    070    }
    071    /**
    072     * Gets the current day of month.
    073     *
    074     * @return the current day of month.
    075     */
    076    public int getDayOfMonth() {
    077        return calendar.get(Calendar.DAY_OF_MONTH);
    078    }
    079
    080    /**
    081     * Gets the current day of year.
    082     *
    083     * @return the current day of year.
    084     * @since 3.13.0
    085     */
    086    public int getDayOfYear() {
    087        return calendar.get(Calendar.DAY_OF_YEAR);
    088    }
    089
    090    /**
    091     * Gets the current month.
    092     *
    093     * @return the current month.
    094     */
    095    public int getMonth() {
    096        return calendar.get(Calendar.MONTH);
    097    }
    098
    099    /**
    100     * Gets month names in the requested style.
    101     * @param style Must be a valid {@link Calendar#getDisplayNames(int, int, Locale)} month style.
    102     * @return Styled names of months
    103     */
    104    String[] getMonthDisplayNames(final int style) {
    105        // Unfortunately standalone month names are not available in DateFormatSymbols,
    106        // so we have to extract them.
    107        final Map<String, Integer> displayNames = calendar.getDisplayNames(Calendar.MONTH, style, locale);
    108        if (displayNames == null) {
    109            return null;
    110        }
    111        final String[] monthNames = new String[displayNames.size()];
    112        displayNames.forEach((k, v) -> monthNames[v] = k);
    113        return monthNames;
    114    }
    115
    116    /**
    117     * Gets full standalone month names as used in "LLLL" date formatting.
    118     * @return Long names of months
    119     */
    120    String[] getStandaloneLongMonthNames() {
    121        return getMonthDisplayNames(Calendar.LONG_STANDALONE);
    122    }
    123
    124    /**
    125     * Gets short standalone month names as used in "LLLL" date formatting.
    126     * @return Short names of months
    127     */
    128    String[] getStandaloneShortMonthNames() {
    129        return getMonthDisplayNames(Calendar.SHORT_STANDALONE);
    130    }
    131
    132    /**
    133     * Gets the current year.
    134     *
    135     * @return the current year.
    136     */
    137    public int getYear() {
    138        return calendar.get(Calendar.YEAR);
    139    }
    140}