java 时间（转）

 

原地址：http://www.2cto.com/kf/201301/185008.html

[java]

import java.util.Calendar;

import java.util.Date;

 

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

 

/**

* 日期工具类

* @author WXQ

*

*/

public class DateUtils {

 

private static final Log log = LogFactory.getLog(DateUtils.class);

 

/**

* 取得当前日期是多少周

*

* @param date

* @return

*/

public static int getWeekOfYear(Date date) {

Calendar c = Calendar.getInstance();

c.setFirstDayOfWeek(Calendar.MONDAY);

/**设置一年中第一个星期所需的最少天数，例如，如果定义第一个星期包含一年第一个月的第一天，则使用值 1 调用此方法。

* 如果最少天数必须是一整个星期，则使用值 7 调用此方法。 **/

c.setMinimalDaysInFirstWeek(1);

c.setTime(date);

 

return c.get(Calendar.WEEK_OF_YEAR);

}

 

/**

* 得到某一年周的总数

*

* @param year

* @return

*/

public static int getMaxWeekNumOfYear(int year) {

Calendar c = Calendar.getInstance();

c.set(year, Calendar.DECEMBER, 31, 23, 59, 59);

 

return getWeekOfYear(c.getTime());

}

 

/**

* 得到某年某周的第一天

*

* @param year

* @param week

* @return

*/

public static Date getFirstDayOfWeek(int year, int week) {

Calendar c = Calendar.getInstance();

c.set(Calendar.YEAR, year);

c.set(Calendar.WEEK_OF_YEAR, week);

c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);//设置周一

c.setFirstDayOfWeek(Calendar.MONDAY);

 

return c.getTime();

}

 

/**

* 得到某年某周的最后一天

*

* @param year

* @param week

* @return

*/

public static Date getLastDayOfWeek(int year, int week) {

Calendar c = Calendar.getInstance();

c.set(Calendar.YEAR, year);

c.set(Calendar.WEEK_OF_YEAR, week);

c.setFirstDayOfWeek(Calendar.MONDAY);

c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 6); // Sunday

 

return c.getTime();

}

 

/**

* 得到某年某月的第一天

*

* @param year

* @param month

* @return

*/

public static Date getFirstDayOfMonth(int year, int month) {

Calendar c = Calendar.getInstance();

c.set(Calendar.YEAR, year);

c.set(Calendar.MONTH, month-1);

c.set(Calendar.DAY_OF_MONTH, c.getActualMinimum(Calendar.DAY_OF_MONTH));

 

return c.getTime();

}

 

/**

* 得到某年某月的最后一天

*

* @param year

* @param month

* @return

*/

public static Date getLastDayOfMonth(int year, int month) {

Calendar c = Calendar.getInstance();

c.set(Calendar.YEAR, year);

c.set(Calendar.MONTH, month-1);

c.set(Calendar.DAY_OF_MONTH, c.getActualMaximum(Calendar.DAY_OF_MONTH));

 

return c.getTime();

}

 

/**

* 得到某年某季度第一天

*

* @param year

* @param quarter

* @return

*/

public static Date getFirstDayOfQuarter(int year, int quarter) {

int month = 0;

if (quarter > 4) {

return null;

} else {

month = (quarter - 1) * 3 + 1;

}

return getFirstDayOfMonth(year, month);

}

 

/**

* 得到某年某季度最后一天

*

* @param year

* @param quarter

* @return

*/

public static Date getLastDayOfQuarter(int year, int quarter) {

int month = 0;

if (quarter > 4) {

return null;

} else {

month = quarter * 3;

}

return getLastDayOfMonth(year, month);

}

 

/**

* 得到某年第一天

*

* @param year

* @return

*/

public static Date getFirstDayOfYear(int year) {

return getFirstDayOfQuarter(year,1);

}

 

/**

* 得到某年最后一天

*

* @param year

* @return

*/

public static Date getLastDayOfYear(int year) {

return getLastDayOfQuarter(year,4);

}

 

public static void main(String[] args) {

log.info(getFirstDayOfWeek(2013,1));

log.info(getLastDayOfWeek(2013,1));

 

log.info(getFirstDayOfMonth(2013,2));

log.info(getLastDayOfMonth(2013,2));

 

log.info(getFirstDayOfQuarter(2013,2));

log.info(getLastDayOfQuarter(2013,2));

 

log.info(getFirstDayOfYear(2013));

log.info(getLastDayOfYear(2013));

 

}

}