Java日期操作常用方法

/** * 取得指定月份的第一天

*

* @param strdate String

* @return String

*/

public String getMonthBegin(String strdate)

{

java.util.Date date = parseFormatDate(strdate);

return formatDateByFormat(date,"yyyy-MM") + "-01";

}

/**

* 取得指定月份的最后一天

*

* @param strdate String

* @return String

*/

public String getMonthEnd(String strdate)

{

java.util.Date date = parseFormatDate(getMonthBegin(strdate));

Calendar calendar = Calendar.getInstance();

calendar.setTime(date);

calendar.add(Calendar.MONTH,1);

calendar.add(Calendar.DAY_OF_YEAR, -1);

return formatDate(calendar.getTime());

}

/**

* 常用的格式化日期

*

* @param date Date

* @return String

*/

public String formatDate(java.util.Date date)

{

return formatDateByFormat(date,"yyyy-MM-dd");

}

/**

* 以指定的格式来格式化日期

*

* @param date Date

* @param format String

* @return String

*/

public String formatDateByFormat(java.util.Date date,String format)

{

String result = "";

if(date != null)

{

try

{

SimpleDateFormat sdf = new SimpleDateFormat(format);

result = sdf.format(date);

}

catch(Exception ex)

{

LOGGER.info("date:" + date);

ex.printStackTrace();

}

}

return result;

}

/**

* 日期操作

*

* @author xxx

* @version 2.0 jdk1.4.0 tomcat5.1.0 * Updated Date:2005/03/10

*/

public class DateUtil {

/**

* 格式化日期

*

* @param dateStr

* 字符型日期

* @param format

* 格式

* @return 返回日期

*/

public static java.util.Date parseDate(String dateStr, String format) {

java.util.Date date = null;

try {

java.text.DateFormat df = new java.text.SimpleDateFormat(format);

String dt=Normal.parse(dateStr).replaceAll(

"-", "/");

if((!dt.equals(""))&&(dt.length()<format.length())){

dt+=format.substring(dt.length()).replaceAll("[YyMmDdHhSs]","0");

}

date = (java.util.Date) df.parse(dt);

} catch (Exception e) {

}

return date;

}

public static java.util.Date parseDate(String dateStr) {

return parseDate(dateStr, "yyyy/MM/dd");

}

public static java.util.Date parseDate(java.sql.Date date) {

return date;

}

public static java.sql.Date parseSqlDate(java.util.Date date) {

if (date != null)

return new java.sql.Date(date.getTime());

else

return null;

}

public static java.sql.Date parseSqlDate(String dateStr, String format) {

java.util.Date date = parseDate(dateStr, format);

return parseSqlDate(date);

}

public static java.sql.Date parseSqlDate(String dateStr) {

return parseSqlDate(dateStr, "yyyy/MM/dd");

}

public static java.sql.Timestamp parseTimestamp(String dateStr,

String format) {

java.util.Date date = parseDate(dateStr, format);

if (date != null) {

long t = date.getTime();

return new java.sql.Timestamp(t);

} else

return null;

}

public static java.sql.Timestamp parseTimestamp(String dateStr) {

return parseTimestamp(dateStr, "yyyy/MM/dd HH:mm:ss");

}

/**

* 格式化输出日期

*

* @param date

* 日期

* @param format

* 格式

* @return 返回字符型日期

*/

public static String format(java.util.Date date, String format) {

String result = "";

try {

if (date != null) {

java.text.DateFormat df = new java.text.SimpleDateFormat(format);

result = df.format(date);

}

} catch (Exception e) {

}

return result;

}

public static String format(java.util.Date date) {

return format(date, "yyyy/MM/dd");

}

/**

* 返回年份

*

* @param date

* 日期

* @return 返回年份

*/

public static int getYear(java.util.Date date) {

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

c.setTime(date);

return c.get(java.util.Calendar.YEAR);

}

/**

* 返回月份

*

* @param date

* 日期

* @return 返回月份

*/

public static int getMonth(java.util.Date date) {

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

c.setTime(date);

return c.get(java.util.Calendar.MONTH) + 1;

}

/**

* 返回日份

*

* @param date

* 日期

* @return 返回日份

*/

public static int getDay(java.util.Date date) {

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

c.setTime(date);

return c.get(java.util.Calendar.DAY_OF_MONTH);

}

/**

* 返回小时

*

* @param date

* 日期

* @return 返回小时

*/

public static int getHour(java.util.Date date) {

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

c.setTime(date);

return c.get(java.util.Calendar.HOUR_OF_DAY);

}

/**

* 返回分钟

*

* @param date

* 日期

* @return 返回分钟

*/

public static int getMinute(java.util.Date date) {

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

c.setTime(date);

return c.get(java.util.Calendar.MINUTE);

}

/**

* 返回秒钟

*

* @param date

* 日期

* @return 返回秒钟

*/

public static int getSecond(java.util.Date date) {

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

c.setTime(date);

return c.get(java.util.Calendar.SECOND);

}

/**

* 返回毫秒

*

* @param date

* 日期

* @return 返回毫秒

*/

public static long getMillis(java.util.Date date) {

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

c.setTime(date);

return c.getTimeInMillis();

}

/**

* 返回字符型日期

*

* @param date

* 日期

* @return 返回字符型日期

*/

public static String getDate(java.util.Date date) {

return format(date, "yyyy/MM/dd");

}

/**

* 返回字符型时间

*

* @param date

* 日期

* @return 返回字符型时间

*/

public static String getTime(java.util.Date date) {

return format(date, "HH:mm:ss");

}

/**

* 返回字符型日期时间

*

* @param date

* 日期

* @return 返回字符型日期时间

*/

public static String getDateTime(java.util.Date date) {

return format(date, "yyyy/MM/dd HH:mm:ss");

}

/**

* 日期相加

*

* @param date

* 日期

* @param day

* 天数

* @return 返回相加后的日期

*/

public static java.util.Date addDate(java.util.Date date, int day) {

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

c.setTimeInMillis(getMillis(date) + ((long) day) * 24 * 3600 * 1000);

return c.getTime();

}

/**

* 日期相减

*

* @param date

* 日期

* @param date1

* 日期

* @return 返回相减后的日期

*/

public static int diffDate(java.util.Date date, java.util.Date date1) {

return (int) ((getMillis(date) - getMillis(date1)) / (24 * 3600 * 1000));

}

}

Calendar now = Calendar.getInstance();

int year = now.get(Calendar.YEAR);

int date = now.get(Calendar.DAY_OF_MONTH);

int month = now.get(Calendar.MONTH) + 1;

int hour = now.get(Calendar.HOUR);

int min = now.get(Calendar.MINUTE);

int sec = now.get(Calendar.SECOND);

import java.sql.Timestamp;

import java.text.SimpleDateFormat;

import java.util.*;

/**

* @李春雷

*

public class ManageWeek {

//判断两个日期是否在同一周

boolean isSameWeekDates(Date date1, Date date2) {

Calendar cal1 = Calendar.getInstance();

Calendar cal2 = Calendar.getInstance();

cal1.setTime(date1);

cal2.setTime(date2);

int subYear = cal1.get(Calendar.YEAR) - cal2.get(Calendar.YEAR);

if (0 == subYear) {

if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR))

return true;

}

else if (1 == subYear && 11 == cal2.get(Calendar.MONTH)) {

// 如果12月的最后一周横跨来年第一周的话则最后一周即算做来年的第一周

if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR))

return true;

}

else if (-1 == subYear && 11 == cal1.get(Calendar.MONTH)) {

if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR))

return true;

}

return false;

}

//产生周序列

public static String getSeqWeek(){

Calendar c = Calendar.getInstance(Locale.CHINA);

String week = Integer.toString(c.get(Calendar.WEEK_OF_YEAR));

if(week.length()==1)week = "0" + week;

String year = Integer.toString(c.get(Calendar.YEAR));

return year+week;

}

//获得周一的日期

public static String getMonday(Date date){

Calendar c = Calendar.getInstance();

c.setTime(date);

c.set(Calendar.DAY_OF_WEEK,Calendar.MONDAY);

return new SimpleDateFormat("yyyy-MM-dd").format(c.getTime());

}

//获得周五的日期

public static String getFriday(Date date){

Calendar c = Calendar.getInstance();

c.setTime(date);

c.set(Calendar.DAY_OF_WEEK,Calendar.FRIDAY);

return new SimpleDateFormat("yyyy-MM-dd").format(c.getTime());

}

public static void main(String[] args){

}

}