DateUtil80.java

package cn.chnmuseum.party.common.util;

import java.time.*;
import java.time.format.DateTimeFormatter;
import java.util.Date;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

public class DateUtil80 {

    // 格式：年－月－日 小时：分钟：秒
    public static final String FORMAT_ONE = "yyyy-MM-dd HH:mm:ss";

    public static final String FORMAT_T = "yyyy-MM-ddTHH:mm:ss";

    // 格式：年－月－日 小时：分钟
    public static final String FORMAT_TWO = "yyyy-MM-dd HH:mm";

    // 格式：年－月－日
    public static final String LONG_DATE_FORMAT = "yyyy-MM-dd";

    // 格式：月－日
    public static final String SHORT_DATE_FORMAT = "MM-dd";

    // 格式：小时：分钟：秒
    public static final String LONG_TIME_FORMAT = "HH:mm:ss";

    // 格式：年-月
    public static final String MONTG_DATE_FORMAT = "yyyy-MM";

    // 格式：年-月
    public static final String Chinese_DATE_FORMAT = "yyyy年MM月dd日 HH:mm";

    private static final ConcurrentMap<String, DateTimeFormatter> FORMATTER_CACHE = new ConcurrentHashMap<>();

    private static final int PATTERN_CACHE_SIZE = 500;

    /**
     * Date转换为格式化时间
     *
     * @param date    date
     * @param pattern 格式
     * @return
     */
    public static String format(Date date, String pattern) {
        return format(LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault()), pattern);
    }

    /**
     * localDateTime转换为格式化时间
     *
     * @param localDateTime localDateTime
     * @param pattern       格式
     * @return
     */
    public static String format(LocalDateTime localDateTime, String pattern) {
        DateTimeFormatter formatter = createCacheFormatter(pattern);
        return localDateTime.format(formatter);
    }

    /**
     * 格式化字符串转为Date
     *
     * @param time    格式化时间
     * @param pattern 格式
     * @return
     */
    public static Date parseDate(String time, String pattern) {
        return Date.from(parseLocalDateTime(time, pattern).atZone(ZoneId.systemDefault()).toInstant());
    }

    /**
     * 格式化字符串转为Date
     *
     * @return
     */
    public static Date getCurrDateTime() {
        LocalDateTime localDateTime = LocalDateTime.now();
        ZoneId zone = ZoneId.systemDefault();
        Instant instant = localDateTime.atZone(zone).toInstant();
        return Date.from(instant);
    }

    /**
     * 格式化字符串转为Date
     *
     * @return
     */
    public static Date getCurrDate() {
        ZoneId zoneId = ZoneId.systemDefault();
        LocalDate localDate = LocalDate.now();
        ZonedDateTime zdt = localDate.atStartOfDay(zoneId);
        return Date.from((zdt).toInstant());
    }

    //LocalDateTime -> Date
    public static Date asDate(LocalDateTime localDateTime) {
        return Date.from(localDateTime.atZone(ZoneId.of("Asia/Shanghai")).toInstant());
    }

    /**
     * 格式化字符串转为LocalDateTime
     *
     * @param time    格式化时间
     * @param pattern 格式
     * @return
     */
    public static LocalDateTime parseLocalDateTime(String time, String pattern) {
        DateTimeFormatter formatter = createCacheFormatter(pattern);
        return LocalDateTime.parse(time, formatter);
    }

    /**
     * 将long类型的timestamp转为LocalDateTime
     *
     * @param timestamp
     * @return
     */
    public static LocalDateTime getDateTimeOfTimestamp(long timestamp) {
        Instant instant = Instant.ofEpochMilli(timestamp);
        ZoneId zone = ZoneId.systemDefault();
        return LocalDateTime.ofInstant(instant, zone);
    }

    /**
     * 在缓存中创建DateTimeFormatter
     *
     * @param pattern 格式
     * @return
     */
    private static DateTimeFormatter createCacheFormatter(String pattern) {
        if (pattern == null || pattern.length() == 0) {
            throw new IllegalArgumentException("Invalid pattern specification");
        }
        DateTimeFormatter formatter = FORMATTER_CACHE.get(pattern);
        if (formatter == null) {
            if (FORMATTER_CACHE.size() < PATTERN_CACHE_SIZE) {
                formatter = DateTimeFormatter.ofPattern(pattern);
                DateTimeFormatter oldFormatter = FORMATTER_CACHE.putIfAbsent(pattern, formatter);
                if (oldFormatter != null) {
                    formatter = oldFormatter;
                }
            }
        }

        return formatter;
    }

}