Java中时间类转换Date、Calender 、LocalDateTime
package com.ptool.date;
import lombok.AllArgsConstructor;
import lombok.Getter;
import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
/**
* 时间工具类，主要用于三大时间类的关系转换
* @author PanXu
*/
public class DateUtils {
/**
* 时间格式和对应正则
*/
@AllArgsConstructor
enum TIME_FORMAT{
/**
* 时间格式为强校验
*/
STANDARD("yyyy-MM-dd HH:mm:ss", "^([1-2][0-9][0-9][0-9]-[0-1][0-9]-[0-3]{0,1}[0-9])\\s(20|21|22|23|[0-1]\\d):[0-5]\\d:[0-5]\\d");
/**
* 时间格式
*/
@Getter
private final String value;
/**
* 正则
*/
@Getter
private final String regex;
/**
* 标准时间格式校验
* @param timeStr
* @return
*/
public Boolean checkStandardTimeStr(String timeStr){
if ( timeStr == null || timeStr.length() < 1){
return false;
}
if( timeStr.matches(STANDARD.getRegex())){
return true;
}
return false;
}
}
/**
* date 转 标准时间字符
* @param date
* @return
*/
public static String dateToStandardString(Date date){
if( date == null){
return null;
}
return new SimpleDateFormat(TIME_FORMAT.STANDARD.getValue()).format(date);
}
/**
* Calendar 转 标准时间字符
* @param calendar
* @return
*/
public static String calendarToStandardString(Calendar calendar){
if( calendar == null){
return null;
}
return new SimpleDateFormat(TIME_FORMAT.STANDARD.getValue()).format(calendar.getTimeInMillis());
}
/**
* localDateTime 转 标准时间字符
* @param localDateTime
* @return
*/
public static String localDateTimeToStandardString(LocalDateTime localDateTime){
if( localDateTime == null ){
return null;
}
return localDateTime.format(DateTimeFormatter.ofPattern(TIME_FORMAT.STANDARD.getValue()));
}
/**
* 标准时间字符 转 Date
* @param timeStr
* @return
*/
public static Date standardTimeStrToDate(String timeStr){
if( timeStr == null){
return null;
}
if( TIME_FORMAT.STANDARD.checkStandardTimeStr(timeStr)){
try {
return new SimpleDateFormat(TIME_FORMAT.STANDARD.getValue()).parse(timeStr);
}catch (Exception e){
// 格式强校验
e.printStackTrace();
}
}
return null;
}
/**
* 标准时间字符 转 Calendar
* @param timeStr
* @return
*/
public static Calendar standardTimeStrToCalendar(String timeStr){
if( timeStr == null){
return null;
}
if( TIME_FORMAT.STANDARD.checkStandardTimeStr(timeStr)){
try {
Calendar calendar = Calendar.getInstance();
Date date = new SimpleDateFormat(TIME_FORMAT.STANDARD.getValue()).parse(timeStr);
calendar.setTime(date);
return calendar;
}catch (Exception e){
// 格式强校验
e.printStackTrace();
}
}
return null;
}
/**
* 标准时间字符 转 localDateTime
* @param timeStr
* @return
*/
public static LocalDateTime standardTimeStrToLocalDateTime(String timeStr){
if( timeStr == null){
return null;
}
if( TIME_FORMAT.STANDARD.checkStandardTimeStr(timeStr)){
return LocalDateTime.parse(timeStr,DateTimeFormatter.ofPattern(TIME_FORMAT.STANDARD.getValue()));
}
return null;
}
/**
* 时间对象转标准输出
* @param obj
* @return
*/
public static String objectToStandardTimeStr(Object obj){
if( obj == null){
return null;
}
if( obj instanceof Date){
return dateToStandardString((Date) obj);
}
if( obj instanceof Calendar){
return calendarToStandardString((Calendar) obj);
}
if( obj instanceof LocalDateTime){
return localDateTimeToStandardString((LocalDateTime) obj);
}
return null;
}
/**
* date 转 LocalDateTime
* @param date
* @return
*/
public static LocalDateTime dateToLocalDateTime(Date date) {
if( date == null ){
return null;
}
return date.toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();
}
/**
* LocalDateTime 转 date
* @param localDateTime
* @return
*/
public static Date localDateTimeToDate(LocalDateTime localDateTime) {
if (localDateTime == null) {
return null;
}
return Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
}
/**
* Calendar 转 date
* @param calendar
* @return
*/
public static Date calenderToDate(Calendar calendar){
if (calendar == null) {
return null;
}
return new Date(calendar.getTimeInMillis());
}
/**
* date 转 Calendar
* @param date
* @return
*/
public static Calendar dateToCalendar(Date date){
if (date == null) {
return null;
}
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar;
}
/**
* Calendar 转 LocalDateTime
* @param calendar
* @return
*/
public static LocalDateTime calenderToLocalDateTime(Calendar calendar){
if (calendar == null) {
return null;
}
return LocalDateTime.ofInstant(calendar.toInstant(), ZoneOffset.systemDefault());
}
/**
* LocalDateTime 转 Calendar
* @param localDateTime
* @return
*/
public static Calendar localDateTimeToCalender(LocalDateTime localDateTime){
if (localDateTime == null) {
return null;
}
return GregorianCalendar.from(ZonedDateTime.of(localDateTime, ZoneId.systemDefault()));
}
/**
* 获得当天的起始时间
* @return
*/
public static String getTodayStartStr(){
return getTimeStartOrEndStr(new Date(),1);
}
/**
* 获得当天的结束时间
* @return
*/
public static String getTodayEndStr(){
return getTimeStartOrEndStr(new Date(),2);
}
/**
*
* @param date
* @param type 1-开始时间 2-结束时间
* @return
*/
public static String getTimeStartOrEndStr(Date date, Integer type){
// 开始时间
if( Integer.valueOf(1).equals(type)){
Calendar calendar = dateToCalendar(date);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MILLISECOND, 0);
return calendarToStandardString(calendar);
}
// 结束时间
if( Integer.valueOf(2).equals(type)){
Calendar calendar = dateToCalendar(date);
calendar.set(Calendar.SECOND, 59);
calendar.set(Calendar.MINUTE, 59);
calendar.set(Calendar.HOUR_OF_DAY, 23);
calendar.set(Calendar.MILLISECOND, 0);
return calendarToStandardString(calendar);
}
return null;
}
}