Apakah kaedah untuk menulis kelas alat tarikh Java?
- 王林ke hadapan
- 2023-05-20 16:22:061089semak imbas
Kelas alat tarikh Java ditulis
Tukar rentetan kepada tarikh yang sepadan
Date date = simpleDateFormat.parse(string);
Tukar tarikh kepada rentetan
String string = simpleDateFormat.format(date);
Nota bahawa pengecualian akan dilemparkan kerana format yang mungkin ditakrifkan tidak sepadan dengan format yang disediakan oleh rentetan sebenar.
Tukar tarikh aksara Cina tahun, bulan dan hari kepada tarikh dengan - - pemisah
public static void main(String[] args) throws ParseException {
//统一日期格式
String StrVal = "2018年05月22日";
Date d1 = new SimpleDateFormat("yyyy年MM月dd日").parse(StrVal);
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
String time = format.format(d1);
System.out.println(time);
}
/**
* 将日期对象格式化为指定格式的日期字符串
* @param date 传入的日期对象
* @param format 格式
* @return
*/
public static String formatDate(Date date,String format){
String result="";
SimpleDateFormat sdf=new SimpleDateFormat(format);
if(date!=null){
result=sdf.format(date);
}
return result;
}
/**
* 将日期字符串转换成一个日期对象
* @param dateStr 日期字符串
* @param format 格式
* @return
* @throws ParseException
*/
public static Date formatDate(String dateStr,String format) throws ParseException{
SimpleDateFormat sdf=new SimpleDateFormat(format);
return sdf.parse(dateStr);
}
public static void main(String[] args) throws ParseException {
Date date=new Date();
System.out.println(formatDate(date,"yyyy-MM-dd"));
System.out.println(formatDate(date,"yyyy-MM-dd HH:mm:ss"));
System.out.println(formatDate(date,"yyyy年MM月dd日HH时mm分ss秒"));
String dataStr="1989-11-02 18:01:41";
Date date2=formatDate(dataStr,"yyyy-MM-dd HH:mm:ss");
System.out.println(formatDate(date2,"yyyy-MM-dd HH:mm:ss"));
}Jalankan output:
2016-11 -02
2016-11-02 18:06:50
November 02, 2016 18:06:50
1989-11-02 18:02-1989 :41
Kelas SimpleDateFormat digunakan terutamanya untuk penukaran jenis tarikh, pemformatan tarikh yang biasa digunakan
public static void main(String[] args) {
//默认输出格式
Date date=new Date();
System.out.println(date);
//日期格式化显示，首先定义格式
SimpleDateFormat sdf1=new SimpleDateFormat("yyyyMMdd");
SimpleDateFormat sdf2=new SimpleDateFormat("yyyy-MM-dd");
SimpleDateFormat sdf3=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
SimpleDateFormat sdf4=new SimpleDateFormat("yyyy年MM月dd日HH时mm分ss秒");
//将格式应用于日期
System.out.println(sdf1.format(date));
System.out.println(sdf2.format(date));
System.out.println(sdf3.format(date));
System.out.println(sdf4.format(date));
}
Kendalian masa kelas kalendar JavaCalendar
Kalendar mempunyai DAY_OF_WEEK yang boleh mengembalikan hari dalam seminggu; >Kendalikan kalendar
import java.util.Calendar;
public class Test {
public static void main(String[] args) {
String[] weekDays = {"星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"};
Calendar calendar=Calendar.getInstance();
System.out.println("今天是"+weekDays[calendar.get(Calendar.DAY_OF_WEEK)-1]);
}
}
Dapatkan masa
Biasa digunakan untuk menetapkan nilai tahun, bulan, hari, jam, nilai 6 minit dan saat, sila ambil perhatian bahawa subskrip bulan bermula dari 0, jadi untuk mendapatkan bulan, +1 Tetapkan pada tarikh tertentu, anda boleh menetapkan tahun, bulan, hari, jam, minit dan saat pada satu masa Sejak langganan bulan bermula dari 0, bulan perlu -1 public static void main(String[] args) {
//默认输出格式
Date now = new Date();
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
String time = format.format(now);
System.out.println(time);
Calendar calendar = Calendar.getInstance();
calendar.setTime(now);
calendar.add(Calendar.MONTH, 1);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String nowTime = sdf.format(calendar.getTime());
System.out.println(nowTime);
calendar.add(Calendar.MONTH, -2);
String nowTime2 = sdf.format(calendar.getTime());
System.out.println(nowTime2);
}
Pengiraan masa
public static void main(String[] args) {
//默认输出格式
Date now = new Date();
SimpleDateFormat nowSdf = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(nowSdf.format(now));
Calendar calendar = Calendar.getInstance();
// 赋值时年月日时分秒常用的6个值，注意月份下标从0开始，所以取月份要+1
System.out.println("年:" + calendar.get(Calendar.YEAR));
System.out.println("月:" + (calendar.get(Calendar.MONTH) + 1));
System.out.println("日:" + calendar.get(Calendar.DAY_OF_MONTH));
System.out.println("时:" + calendar.get(Calendar.HOUR_OF_DAY));
System.out.println("分:" + calendar.get(Calendar.MINUTE));
System.out.println("秒:" + calendar.get(Calendar.SECOND));
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String nowTime2 = sdf.format(calendar.getTime());
System.out.println(nowTime2);
}
Pengiraan tarikh
Dapatkan bilangan hari minimum dan maksimum dalam bulan ini
public static void main(String[] args) {
//默认输出格式
Date now = new Date();
SimpleDateFormat nowSdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println(nowSdf.format(now));
Calendar calendar = Calendar.getInstance();
calendar.set(2013, 5, 4, 13, 44, 51);
calendar.set(Calendar.YEAR, 2014);//年
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String nowTime = sdf.format(calendar.getTime());
System.out.println(nowTime);
calendar.set(Calendar.MONTH, 7);//月（月份0代表1月）
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String nowTime1 = sdf1.format(calendar.getTime());
System.out.println(nowTime1);
calendar.set(Calendar.DATE, 11);//日
calendar.set(Calendar.HOUR_OF_DAY, 15);//时
calendar.set(Calendar.MINUTE, 33);//分
calendar.set(Calendar.SECOND, 32);//秒
}
Dapatkan Isnin minggu ini, Isnin minggu lepas, Isnin minggu ini
public static void main(String[] args) {
//默认输出格式
Date now = new Date();
SimpleDateFormat nowSdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println(nowSdf.format(now));
Calendar calendar = Calendar.getInstance();
calendar.setTime(now);
calendar.add(Calendar.YEAR, 1);//年
calendar.add(Calendar.MONTH, 1);//月
calendar.add(Calendar.DATE, 1);//日
//calendar.add(Calendar.DAY_OF_YEAR, 1);//今年的第 N 天
//calendar.add(Calendar.DAY_OF_MONTH, 1); // 本月第 N 天
//calendar.add(Calendar.DAY_OF_WEEK, 1);// 本周几
calendar.add(Calendar.HOUR_OF_DAY, -1);//时
calendar.add(Calendar.MINUTE, 1);//分
calendar.add(Calendar.SECOND, 1);//秒
//calendar.add(calendar.WEEK_OF_MONTH, 1);//增加一个礼拜
//calendar.add(calendar.WEEK_OF_YEAR,1);//增加一个礼拜
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String nowTime1 = sdf1.format(calendar.getTime());
System.out.println(nowTime1);
}
Pengiraan hari
Kelas Penggunaan Tarikh untuk mengira perbezaan tarikh
public static void main(String[] args) {
//默认输出格式
Date now = new Date();
SimpleDateFormat nowSdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Calendar calendar = Calendar.getInstance();
int firstD = calendar.getActualMinimum(calendar.DAY_OF_MONTH);
int lastD = calendar.getActualMaximum(calendar.DAY_OF_MONTH);
System.out.println("获取本月的第一天和最后天：" + firstD +"," + lastD);
} public static Date geLastWeekMonday(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(getThisWeekMonday(date));
cal.add(Calendar.DATE, -7);
return cal.getTime();
}
public static Date getThisWeekMonday(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
// 获得当前日期是一个星期的第几天
int dayWeek = cal.get(Calendar.DAY_OF_WEEK);
if (1 == dayWeek) {
cal.add(Calendar.DAY_OF_MONTH, -1);
}
// 设置一个星期的第一天，按中国的习惯一个星期的第一天是星期一
cal.setFirstDayOfWeek(Calendar.MONDAY);
// 获得当前日期是一个星期的第几天
int day = cal.get(Calendar.DAY_OF_WEEK);
// 根据日历的规则，给当前日期减去星期几与一个星期第一天的差值
cal.add(Calendar.DATE, cal.getFirstDayOfWeek() - day);
return cal.getTime();
}
public static Date getNextWeekMonday(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(getThisWeekMonday(date));
cal.add(Calendar.DATE, 7);
return cal.getTime();
}
public static void main(String[] args) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
try {
Date date = sdf.parse("2017-09-10");
System.out.println("今天是" + sdf.format(date));
System.out.println("上周一" + sdf.format(geLastWeekMonday(date)));
System.out.println("本周一" + sdf.format(getThisWeekMonday(date)));
System.out.println("下周一" + sdf.format(getNextWeekMonday(date)));
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
Calendar love = Calendar.getInstance();
Calendar now = Calendar.getInstance();
love.set(2016, 8, 6); //真实的日期是2016-9-6;
int days = (int) ((now.getTimeInMillis() - love.getTimeInMillis()) / (24 * 60 * 60 * 1000.0));
System.out.println(days);
}rrreeAtas ialah kandungan terperinci Apakah kaedah untuk menulis kelas alat tarikh Java?. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!