java中对日期的处理需要用到calendar类，其中有几个方法在使用时需要新手注意

发布网友 发布时间：2022-04-24 06:12

我来回答

共2个回答

懂视网 时间：2022-04-24 10:33

 package com.gbcom.system.utils;
import java.sql.Timestamp;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import javax.xml.datatype.DatatypeConfigurationException;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.gbcom.op.util.Assert;
import com.hc.core.utils.XMLGregorianCalendarConversionUtils;
/**
 * 服务端日期处理的类
 * 
 */
public class DateUtil {
/**
* 日志记录器
*/
public static final Logger LOG = LoggerFactory.getLogger(DateUtil.class);
/**
* 给指定的日期增加指定的时间
* 
* @param date
*  日期
* @param field
*  如#Calendar.MONTH #Calendar.DAY
* @param amount
*  数目,如1 加一天 -1减一天
* @return 增加指定时间的日期
*/
public static Date add(Date date, int field, int amount) {
Calendar calendar = getCalendar(date);
calendar.add(field, amount);
return calendar.getTime();
}
/**
* 将传入的日期转换成今天的时间
* 
* @param date
*  传入的日期
* @return 返回今天的时间
*/
public static Date getTodayTime(Date date) {
Calendar cNow = getCalendar(new Date());
Calendar calendar = getCalendar(date);
calendar.set(Calendar.YEAR, cNow.get(Calendar.YEAR));
calendar.set(Calendar.MONTH, cNow.get(Calendar.MONTH));
calendar.set(Calendar.DAY_OF_YEAR, cNow.get(Calendar.DAY_OF_YEAR));
return calendar.getTime();
}
/**
* 返回指定日期是一周中的第几天
* 
* @param date
*  指定日期
* @return 返回指定日期是一周中的第几天
*/
public static int getWeek(Date date) {
Calendar calendar = getCalendar(date);
return calendar.get(Calendar.DAY_OF_WEEK);
}
/**
* Date转换成Calendar
* 
* @param date
*  Date
* @return Calendar
*/
public static Calendar getCalendar(Date date) {
if (date == null) {
return null;
}
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar;
}
/**
* 两个日期相减,date1-date2,取得相差几天
* 
* @param date1
*  日期1
* @param date2
*  日期2
* @return 取得相差几天
*/
public static int sub(Date date1, Date date2) {
Assert.notNull(date1);
Assert.notNull(date2);
long tem = date1.getTime() - date2.getTime();
return Integer.parseInt(String.valueOf(tem / (24 * 60 * 60 * 1000)));
}
/**
* 合并时间,
* 
* @param date
*  年月日
* @param time
*  时分秒
* @return 合并后的日期
*/
@SuppressWarnings("deprecation")
public static Date mergeDate(Date date, Date time) {
Calendar calendar = getCalendar(date);
calendar.set(Calendar.MINUTE, time.getMinutes());
calendar.set(Calendar.HOUR_OF_DAY, time.getHours());
return calendar.getTime();
}
/**
* 用默认风格把时间格式化成<code>yyyy-MM-dd HH：mm:ss</code> 的时间字符串
* 
* @author zhaishixi 2013-09-18
* @param date
*  时间字符串
* @return date
*/
public static String format(Object date) {
if (date != null) {
return DateFormat.getDateTimeInstance().format(date);
} else {
return null;
}
}
/**
* 用默认风格把时间格式化成制定格式如<code>（ yyyy-MM-dd HH：mm:ss）</code> 的时间字符串
* 
* @author zhaishixi 2013-09-26
* @param date
*  时间字符串
* @param pattern
*  the pattern describing the date and time format
* @return date
*/
public static String format(Object date, String pattern) {
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
if (date != null) {
return sdf.format(date);
} else {
return null;
}
}
/**
* 用默认风格把date(Object 类型)按指定格式<code>pattern</code>格式化Date类型
* 
* @author zhaishixi 2013-09-26
* @param date
*  时间字符串 * @param pattern the pattern describing the date and
*  time format
* @return date
*/
public static Date parse(Object date, String pattern) {
Date fd = new Date();
if (date == null) {
return null;
}
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
try {
fd = sdf.parse(date.toString());
} catch (ParseException e) {
LOG.error("parse date failed!", e);
}
return fd;
}
/**
* 用默认风格把date(Object 类型)按指定格式<code>pattern</code>格式化Date类型
* 
* @param date
*  要转换的日期
* @param pattern
*  格式
* @return 转换后的日期
*/
public static Date parseDate(Object date, String pattern) {
Date d = new Date();
if (date == null) {
return null;
}
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
String format = sdf.format(date);
try {
d = sdf.parse(format);
} catch (ParseException e) {
e.printStackTrace();
}
return d;
}
/**
* 计算出离<code>beginDate日期data</code>天的日期. <li>若datas小于0表示当前日期之前data天. <li>
* 若datas大于0表当前日期之后data天.
* 
* @author zhaishixi 2013-09-25
* @param beginDate
*  要计算的天数
* @param data
*  间隔
* @return 得到日期 格式：<code>yyyy-MM-dd HH:mm:ss</code>
*/
public static Date getDate(Date beginDate, int data) {
Calendar beginCal = Calendar.getInstance();
beginCal.setTimeInMillis(beginDate.getTime());
GregorianCalendar calendar = new GregorianCalendar(beginCal
.get(Calendar.YEAR), beginCal.get(Calendar.MONTH), beginCal
.get(Calendar.DATE), beginCal.get(Calendar.HOUR_OF_DAY),
beginCal.get(Calendar.MINUTE), beginCal.get(Calendar.SECOND));
calendar.add(GregorianCalendar.DATE, data);
return new Date(calendar.getTimeInMillis());
}
/**
* 将时间（单位为秒） 转化为 ：时 ：分 ： 秒格式
* 
* 该time 并非 {@link Date#getTime()} ,单位为秒
* 
* @param time
*  long
* @return String
*/
public static String valueOfSecond(long time) {
long h = time / 3600;
long m = (time % 3600) / 60;
long s = (time % 3600) % 60;
String value = h + "Basic_hour" + ":" + m + "Basic_min" + ":" + s
+ "Basic_sec";
return value;
}
/**
* 将时间（单位为分钟） 转化为 ：天：时 ：分格式
* 
* 该time 并非 {@link Date#getTime()} ,单位为分钟
* 
* @param time
*  long
* @return String
*/
public static String valueOfMinute(long time) {
long d = time / (24 * 60);
long h = (time % (24 * 60)) / 60;
long m = (time % (24 * 60)) % 60;
String value = d + "Basic_day" + ":" + h + "Basic_hour" + ":" + m
+ "Basic_min";
return value;
}
/**
* 返回当前月前n个月或者后n个月的第一天
* 
* @param num
*  n个月 isPositive 为true表示前，为false表示后
* @param isPositive
*  +/-
* @return n个月第一天
*/
@SuppressWarnings("deprecation")
public static Date getFirstDayOfMonth(int num, boolean isPositive) {
Date date = new Date();
Calendar calendar = Calendar.getInstance();
int year = calendar.getTime().getYear();
int month = calendar.getTime().getMonth();
if (isPositive) {
month = month + num;
} else {
month = month - num;
}
int day = 1;
if (month < 0) {
year = year - 1;
month = 11;
} else if (month > 12) {
year = year + 1;
month = 0;
}
date = new Date(year, month, day);
return date;
}
// ----------------非通用方法，谨慎使用----------------//
/**
* 时间格式转换--cxf不识别java.sql.Timestamp
* 
* @param orgTime
*  java.sql.Timestamp
* @return XMLGregorianCalendar
*/
public static XMLGregorianCalendar timeToXmlDate(java.sql.Timestamp orgTime) {
if (orgTime != null) {
return XMLGregorianCalendarConversionUtils
.asXMLGregorianCalendar(new Date(orgTime.getTime()));
}
return null;
}
/**
* 将xmldate转为timestamp
* 
* @param cal
*  XMLGregorianCalendar
* @return java.sql.Timestamp
*/
public static java.sql.Timestamp xmlDate2Time(XMLGregorianCalendar cal) {
if (cal != null) {
return new java.sql.Timestamp(XMLGregorianCalendarConversionUtils
.asDate(cal).getTime());
}
return null;
}
/**
* 将Date类转换为XMLGregorianCalendar
* 
* @param date
*  Date
* @return XMLGregorianCalendar
*/
public static XMLGregorianCalendar dateToXmlDate(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
DatatypeFactory dtf = null;
try {
dtf = DatatypeFactory.newInstance();
} catch (DatatypeConfigurationException e) {
}
XMLGregorianCalendar dateType = dtf.newXMLGregorianCalendar();
dateType.setYear(cal.get(Calendar.YEAR));
// 由于Calendar.MONTH取值范围为0~11,需要加1
dateType.setMonth(cal.get(Calendar.MONTH) + 1);
dateType.setDay(cal.get(Calendar.DAY_OF_MONTH));
dateType.setHour(cal.get(Calendar.HOUR_OF_DAY));
dateType.setMinute(cal.get(Calendar.MINUTE));
dateType.setSecond(cal.get(Calendar.SECOND));
return dateType;
}
/**
* 将XMLGregorianCalendar转换为Date
* 
* @param cal
*  XMLGregorianCalendar
* @return Date
*/
public static Date xmlDate2Date(XMLGregorianCalendar cal) {
return cal.toGregorianCalendar().getTime();
}
/**
* 获取工作时间：8:30 - 17:30
* 
* @param date
*  String
* @return String[]
* @throws ParseException
*  ParseException
*/
public static String[] getWorkDate(String date) throws ParseException {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
Calendar cd = Calendar.getInstance();
cd.setTime(simpleDateFormat.parse(date));
cd.add(Calendar.HOUR, 7);
cd.add(Calendar.MINUTE, 30);
simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
String[] workDate = new String[2];
workDate[0] = simpleDateFormat.format(cd.getTime());
cd.add(Calendar.HOUR, 10);
workDate[1] = simpleDateFormat.format(cd.getTime());
return workDate;
}
/**
* 获取当天的开始时间
* 
* @param date
*  指定日期
* @return 当前开始日期
*/
public static Date getCurDayStart(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
return calendar.getTime();
}
/**
* 获取本周的开始时间
* 
* @param date
*  指定日期
* @return 本周开始日期
*/
public static Date getCurWeekStart(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.setFirstDayOfWeek(Calendar.MONDAY);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
return calendar.getTime();
}
/**
* 获取当月的开始时间
* 
* @param date
*  指定日期
* @return 当月开始日期
*/
public static Date getCurMonthStart(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.DAY_OF_MONTH, 1);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
return calendar.getTime();
}
/**
* 获取当年的开始日期
* 
* @param date
*  指定日期
* @return 当年的开始日期
*/
public static Date getCurYearStart(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.DAY_OF_YEAR, 1);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
return calendar.getTime();
}
public static Date longToDate(long lg){
//long ,转 date
return new Date(lg);
}
public static long DateToLong(Date date){
return date.getTime();
}
/**
* date对象指向的实体却是一个Timestamp，即date拥有Date类的方法，但被覆盖的方法的执行实体在Timestamp中。
* : (DateUtil.tsToDate)
* @param ts
* @return
*/
public static Date tsToDate(Timestamp ts){
 Date date = new Date(); 
 try { 
  date = ts; 
 } catch (Exception e) { 
  e.printStackTrace(); 
 } 
 return date;
}
public static Timestamp DateToTs(Date date){
Timestamp ts = new Timestamp(date.getTime());
 
return ts;
}
// off checkstyle
public static void main(String[] args) {
System.out.println(new Date());
System.out.println(new Date(System.currentTimeMillis()));
System.out.println(System.currentTimeMillis());
System.out.println(new Date(System.currentTimeMillis()).getTime());
System.out.println(new Date(System.currentTimeMillis()).getTime());
// //
// System.out.println(format(parse("20131111235959","yyyyMMddHHmmss")));
//
// // LOG.info("DATA="+parse("TTT20131111235959","dsdsdsd"));
// long var = 10201;
// System.out.println(valueOfMinute(var));
// System.out.println(valueOfSecond(var));
//
//
//
// Timestamp curTime = new Timestamp(System.currentTimeMillis());
// XMLGregorianCalendar calendar = timeToXmlDate(curTime);
//
// System.out.println("calendar = " + calendar);
//
// Timestamp timestamp = xmlDate2Time(calendar);
// System.out.println("timestamp = " +
// DateTimeHelper.formatTimeGBK(timestamp));
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String time = df.format(getCurWeekStart(new Date()));
System.out.println(time);
}
}

热心网友 时间：2022-04-24 07:41