Java日期格式转换

时间格式转化与计算代码（java）

2007年04月13日星期五13:10*

*

Title: 时间格式转化与计算

*/

package https://www.360docs.net/doc/ae2003922.html,;

import java.util.Calendar;

import java.util.Date;

import java.text.*;

public class DateTime {

public DateTime() {

}

/**

* 取得系统当前时间

* @return String yyyy-mm-dd

*/

public String getCurrentDate() {

Calendar rightNow = Calendar.getInstance();

int year = rightNow.get(rightNow.YEAR);

int month = rightNow.get(rightNow.MONTH) + 1; int day = rightNow.get(rightNow.DATE);

return year + "-" + month + "-" + day;

}

/**

* 取得系统当前时间

* @return String yyyy年mm月dd日

*/

public String getCurrentDate1() {

Calendar rightNow = Calendar.getInstance();

int year = rightNow.get(rightNow.YEAR);

int month = rightNow.get(rightNow.MONTH) + 1; int day = rightNow.get(rightNow.DATE);

return year + "年" + month + "月" + day + "日"; }

/**

* 取得系统当前时间

* @return String yyyymmdd

*/

public String getCurrentDate2() {

Calendar rightNow = Calendar.getInstance();

int year = rightNow.get(rightNow.YEAR);

int month = rightNow.get(rightNow.MONTH) + 1; int day = rightNow.get(rightNow.DATE);

return year + "" + month + "" + day;

}

/**

* 取得系统当前时间

* @return String yyyy-mm

*/

public String getCurrentDate3() {

Calendar rightNow = Calendar.getInstance();

int year = rightNow.get(rightNow.YEAR);

int month = rightNow.get(rightNow.MONTH) + 1; //int day = rightNow.get(rightNow.DATE); return year + "-" + month;

}

/**

* 取得系统当前时间

* @return String yyyyMMddhhmmss

*/

public String getCurrentDate4() {

Calendar c = Calendar.getInstance();

c.add(c.SECOND, 0);

return "" + c.get(c.YEAR) + "" + (c.get(c.MONTH) + 1) + "" + c.get(c.DATE)+""+c.get(c.HOUR_OF_DAY)+""+c.get(c.MINUTE)+" "+c.get(c.SECOND);

}

/**

* 取得系统当前时间

* @return String yyyy-MM-dd hh:mm:ss

*/

/* public String getCurrentDate5() {

SimpleDateFormat simpleDateFormat =new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

java.util.Date date = new java.util.Date();

String time = simpleDateFormat.format(date);

return time;

}

*/

/**

* 取得系统当前时间

* @return String yyyy-MM-dd hh:mm:ss

*/

public String getCurrentDate5(){

Calendar c = Calendar.getInstance();

c.add(c.SECOND, 0);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE)+" "+c.get(c.HOUR_OF_DAY)+":"+c.get(c.MINUTE)+":"+c.get(c.SEC OND);

}

/**

* 取得系统当前时间常用于订单号

* @return String yyyyMMddhhmmss

*/

public String getCurrentDate6() {

Calendar c = Calendar.getInstance();

c.add(c.SECOND, 0);

String year=c.get(c.YEAR)+"";

return "" + year.subSequence(2,year.length())+ "" + (c.get(c.MONTH) + 1) + "" + c.get(c.DATE)+"-"+c.get(c.HOUR_OF_DAY)+""+c.get(c.MINUTE)+ ""+c.get(c.SECOND)+"-"+c.get(https://www.360docs.net/doc/ae2003922.html,LISECOND);

}

/**

* 取得系统当前时间前n个月的相对应的一天

* @param n int

* @return String yyyy-mm-dd

*/

public String getNMonthBeforeCurrentDay(int n) {

Calendar c = Calendar.getInstance();

c.add(c.MONTH, -n);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

}

/**

* 取得系统当前时间后n个月的相对应的一天

* @param n int

* @return String yyyy-mm-dd

*/

public String getNMonthAfterCurrentDay(int n) {

Calendar c = Calendar.getInstance();

c.add(c.MONTH, n);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

}

/**

* 取得系统当前时间前n天

* @param n int

* @return String yyyy-mm-dd

*/

public String getNDayBeforeCurrentDate(int n) {

Calendar c = Calendar.getInstance();

c.add(c.DAY_OF_MONTH, -n);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

}

/**

* 取得系统当前时间后n天

* @param n int

* @return String yyyy-mm-dd

*/

public String getNDayAfterCurrentDate(int n) {

Calendar c = Calendar.getInstance();

c.add(c.DAY_OF_MONTH, n);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

}

//---------------------------------------------------------------------

//取过去一个时间对应的系统当年的一天

public String getCurrentDateAfterPastDate(String sPastDate) {

if (sPastDate != null && !sPastDate.equals("")) {

Date date = switchStringToDate(sPastDate);

Calendar c = Calendar.getInstance();

c.setTime(date);

int iPastYear = c.get(c.YEAR);

Calendar c1 = Calendar.getInstance();

int iCurrentYear = c1.get(c1.YEAR);

c.add(c.YEAR, iCurrentYear - iPastYear);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" +

c.get(c.DATE);

}

else {

return null;

}

}

/**

* 将一个日期字符串转化成日期

* @param sDate String

* @return Date yyyy-mm-dd

*/

public Date switchStringToDate(String sDate) {

Date date = null;

try {

SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");

date = df.parse(sDate);

}

catch (Exception e) {

System.out.println("日期转换失败:" + e.getMessage());

}

return date;

}

/**

* 输入两个字符串型的日期，比较两者的大小

* @param fromDate String

* @param toDate String

* @return boolean before为true

*/

public boolean compareTwoDateBigOrSmall(String fromDate, String toDate) {

Date dateFrom = this.switchStringToDate(fromDate);

Date dateTo = this.switchStringToDate(toDate);

if (dateFrom.before(dateTo)) {

return true;

}

else {

return false;

}

}

/**

* 将一个日期字符串转化成Calendar

* @param sDate String

* @return Calendar

*/

public Calendar switchStringToCalendar(String sDate) { Date date = switchStringToDate(sDate);

Calendar c = Calendar.getInstance();

c.setTime(date);

return c;

}

/**

* 将一个日期转化成Calendar

* @param date Date

* @return Calendar

*/

public Calendar switchStringToCalendar(Date date) {

Calendar c = Calendar.getInstance();

c.setTime(date);

return c;

}

public String string2Date(String dateString)

throws https://www.360docs.net/doc/ae2003922.html,ng.Exception {

/*DateFormat dateFormat;

dateFormat = new SimpleDateFormat("yyyy-MM-dd kk:mm:ss");

dateFormat.setLenient(false);

java.util.Date timeDate = dateFormat.parse(dateString);//util类型

//java.sql.Date dateTime = new java.sql.Date(timeDate.getTime());//sql类型

java.sql.Timestamp dateTime = new java.sql.Timestamp(timeDate.getTime());//Timestamp类型

*/

SimpleDateFormat newk = new SimpleDateFormat ("yyyy.MM.dd hh:mm:ss");

SimpleDateFormat old = new SimpleDateFormat("MMM dd hh:mm:ss yyyy");

String strDate = "Mar 22 00:42:00 2002";

Date d = old.parse(strDate);

System.out.println(newk.format(d));

return newk.format(d);

}

/**

* 取得某个时间前n个月的相对应的一天

* @param sDate String

* @param n int

* @return String yyyy-mm-dd

*/

public String getNMonthBeforeOneDay(String sDate, int n) {

Calendar c = switchStringToCalendar(sDate);

c.add(c.MONTH, -n);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

}

//取得某个时间后n个月的相对应的一天

public String getNMonthAfterOneDay(String sDate, int n) {

Calendar c = switchStringToCalendar(sDate);

c.add(c.MONTH, n);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

}

//取得某个时间前n天,格式为yyyy-mm-dd

public String getNDayBeforeOneDate(String sDate, int n) {

Calendar c = switchStringToCalendar(sDate);

c.add(c.DAY_OF_MONTH, -n);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

}

//取得某个时间后n天,格式为yyyy-mm-dd

public String getNDayAfterOneDate(String sDate, int n) {

Calendar c = switchStringToCalendar(sDate);

c.add(c.DAY_OF_MONTH, n);

return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

}

//判断系统当前时间是不是润年

public boolean isRunNian() {

java.util.Calendar rightNow = java.util.Calendar.getInstance();

int year = rightNow.get(rightNow.YEAR);

if (0 == year % 4 && (year % 100 != 0 || year % 400 == 0)) {

return true;

}

else {

return false;

}

}

public static void main(String args[]) { DateTime a = new DateTime();

try{

System.out.println(a.getCurrentDate6());

System.out.println(a.getCurrentDate6()); }catch(Exception e){System.err.println();}

}