DateUtils 时间工具类

public enum TimeEnum {

    /**
     * 时间格式
     */
    YYYY_MM_DD("yyyy-MM-dd"),

    YYYY_MM_DD_HH_MM_SS("yyyy-MM-dd HH:mm:ss"),

    YYYYMMDDHHMMSS("yyyyMMddHHmmss"),

    YYYY_MM("yyyy/MM/"),

    YYYYMMDD("yyyyMMdd");

    String format;

    TimeEnum(String format) {
        this.format = format;
    }

    public String getFormat() {
        return format;
    }
}

import org.apache.commons.lang.time.FastDateFormat;
import org.springframework.lang.NonNull;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

public class DateUtils {

    private static final FastDateFormat YYYY_MM = FastDateFormat.getInstance(TimeEnum.YYYY_MM.getFormat());   //yyyy/MM/
    private static final FastDateFormat YYYYMMDD = FastDateFormat.getInstance(TimeEnum.YYYYMMDD.getFormat());   //yyyyMMdd
    private static final FastDateFormat YYYY_MM_DD = FastDateFormat.getInstance(TimeEnum.YYYY_MM_DD.getFormat());   // yyyy-MM-dd
    private static final FastDateFormat YYYY_MM_DD_HH_MM_SS = FastDateFormat.getInstance(TimeEnum.YYYY_MM_DD_HH_MM_SS.getFormat());  // yyyy-MM-dd HH:mm:ss
    private static final FastDateFormat YYYYMMDDHHMMSS = FastDateFormat.getInstance(TimeEnum.YYYYMMDDHHMMSS.getFormat());  // yyyyMMddHHmmss
    public static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");  // yyyy-MM-dd HH:mm:ss

    /**
     * 获取当前时间
     *
     * @param timeEnum 时间格式类
     * @param date     时间
     */
    public static String getNowTimeByString(@NonNull TimeEnum timeEnum,@NonNull Date date) {
        switch (timeEnum) {
            case YYYY_MM_DD:
                return YYYY_MM_DD.format(date);
            case YYYYMMDDHHMMSS:
                return YYYYMMDDHHMMSS.format(date);
            case YYYY_MM:
                return YYYY_MM.format(date);
            case YYYYMMDD:
                return YYYYMMDD.format(date);
            case YYYY_MM_DD_HH_MM_SS:
            default:
                return YYYY_MM_DD_HH_MM_SS.format(date);
        }
    }

    /**
     * 指定时间（参数）向前推，或向后推指定时间
     *
     * @param date      时间
     * @param daysCount 天数
     * @param timeEnum  时间格式类
     */
    public static String movePointerTime(Date date, int field, int daysCount, TimeEnum timeEnum) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(field, daysCount);
        return getNowTimeByString(timeEnum, calendar.getTime());
    }

    /**
     * 将本地时间, 转换成目标时区的时间
     * @param sourceDate
     * @param targetZoneId {@link ZoneIds}
     * @return
     */
    public static Date convertTimezone(Date sourceDate, String targetZoneId){
        return convertTimezone(sourceDate, TimeZone.getTimeZone(targetZoneId));
    }

    public static Date convertTimezone(Date sourceDate, String sourceZoneId, String targetZoneId){
        TimeZone sourceTimeZone=TimeZone.getTimeZone(sourceZoneId);
        TimeZone targetTimeZone=TimeZone.getTimeZone(targetZoneId);

        return convertTimezone(sourceDate, sourceTimeZone, targetTimeZone);
    }

    /**
     * 将本地时间,转换成对应时区的时间
     * @param localDate
     * @param targetTimezone 转换成目标时区所在的时间
     * @return
     */
    public static Date convertTimezone(Date localDate, TimeZone targetTimezone){
        return convertTimezone(localDate, TimeZone.getDefault(), targetTimezone);
    }

    /**
     * 将sourceDate转换成指定时区的时间
     * @param sourceDate
     * @param sourceTimezone sourceDate所在的时区
     * @param targetTimezone 转化成目标时间所在的时区
     * @return
     */
    public static Date convertTimezone(Date sourceDate, TimeZone sourceTimezone, TimeZone targetTimezone){

        Calendar calendar=Calendar.getInstance();
        // date.getTime() 为时间戳, 为格林尼治到系统现在的时间差,世界各个地方获取的时间戳是一样的,
        // 格式化输出时,因为设置了不同的时区,所以输出不一样
        long sourceTime=sourceDate.getTime();
        calendar.setTimeZone(sourceTimezone);
        calendar.setTimeInMillis(sourceTime);// 设置之后,calendar会计算各种filed对应的值,并保存
        //获取源时区的到UTC的时区差
        int sourceZoneOffset=calendar.get(Calendar.ZONE_OFFSET);
        calendar.setTimeZone(targetTimezone);
        calendar.setTimeInMillis(sourceTime);
        int targetZoneOffset=calendar.get(Calendar.ZONE_OFFSET);
        int targetDaylightOffset=calendar.get(Calendar.DST_OFFSET); // 夏令时
        long targetTime=sourceTime+ (targetZoneOffset+targetDaylightOffset) -sourceZoneOffset;
        return new Date(targetTime);
    }

    /**
     * 时间追加\减去几天
     */
    public static String minusTime(@NonNull TimeEnum timeEnum,@NonNull String time, @NonNull Integer count) throws ParseException {
        SimpleDateFormat dateFormat = new SimpleDateFormat(timeEnum.getFormat());
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(dateFormat.parse(time));
        calendar.add(Calendar.DAY_OF_WEEK, count);
        return dateFormat.format(calendar.getTime());
    }

    public static void main(String[] args) throws ParseException {
        System.out.println(minusTime(TimeEnum.YYYYMMDD, "20200709", -1));
    }

}