java-日期取特定值

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

/**

* @author Gerrard

*/

public class TestGetWeek {

public static void main(String[] args) {

int currentMaxDays = getCurrentMonthDay();

int maxDaysByDate = getDaysByYearMonth(2012, 11);

String week = getDayOfWeekByDate("2012-12-25");

System.out.println("本月天数：" + currentMaxDays);

System.out.println("2012年11月天数：" + maxDaysByDate);

System.out.println("2012-12-25是：" + week);

}

/**

* 获取当月的 天数

* */

public static int getCurrentMonthDay() {

Calendar a = Calendar.getInstance();

a.set(Calendar.DATE, 1);

a.roll(Calendar.DATE, -1);

int maxDate = a.get(Calendar.DATE);

return maxDate;

}

/**

* 根据年 月 获取对应的月份 天数

* */

public static int getDaysByYearMonth(int year, int month) {

Calendar a = Calendar.getInstance();

a.set(Calendar.YEAR, year);

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

a.set(Calendar.DATE, 1);

a.roll(Calendar.DATE, -1);

int maxDate = a.get(Calendar.DATE);

return maxDate;

}

/**

* 根据日期获取对应的日 * */

public static int getCurrentDateToDay(String currentDate){

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

Calendar cal = Calendar.getInstance();

try {

cal.setTime(df.parse(currentDate));

} catch (ParseException e) {

e.printStackTrace();

}

return cal.get(Calendar.DATE);

}

/**

* 根据日期 找到对应日期的 星期

*/

public static String getDayOfWeekByDate(String date) {

String dayOfweek = "-1";

try {

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

Date myDate = myFormatter.parse(date);

SimpleDateFormat formatter = new SimpleDateFormat("E");

String str = formatter.format(myDate);

dayOfweek = str;

} catch (Exception e) {

System.out.println("错误!");

}

return dayOfweek;

}

}

获取3天前的日期

//获取开始时间 - 过车数据只查询3天的过车数据

import java.util.Calendar;

Calendar c = Calendar.getInstance();

c.add(Calendar.DATE, -2);

String passUpTime = c.get(Calendar.YEAR) + "-" + (c.get(Calendar.MONTH) + 1) + "-" + c.get(Calendar.DATE) + "@00:00:00";