java 怎么获取一个月的日期

java 怎么获取一个月的日期

//month为两位,例如01
public static Date[] getDates(String year, String month) {
Calendar cal = Calendar.getInstance();
//1.跳转到本月第一天

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM");
sdf.parse(year+"-"+month);
cal.setTime(date);
int maxDate = cal.getMaximum(Calendar.DAY_OF_MONTH);//获取本月日期值
}2013-11-28

Calendar cal = Calendar.getInstance();
// 不加下面2行，就是取当前时间前一个月的第一天及最后一天
cal.set(Calendar.YEAR,2012) ；
cal.set(Calendar.MONTH, 6);
cal.set(Calendar.DAY_OF_MONTH, 1);
cal.add(Calendar.DAY_OF_MONTH, -1);
Date lastDate = cal.getTime();//当前月最后一天

cal.set(Calendar.DAY_OF_MONTH, 1);
Date firstDate = cal.getTime();//当前月第一天2015-07-10

/** * * 获取指定月份的日历信息 * * @param year * 年 * @param month * 月 * @return */public static int[] getMonthCalendar(int year, int month) {Calendar cl = Calendar.getInstance();cl.set(year, month, 1);int firstDay = cl.getMinimum(Calendar.DAY_OF_MONTH);int lastDay = cl.getMaximum(Calendar.DAY_OF_MONTH);int[] day = new int[lastDay];for (int i = 0; i < lastDay; i++) {day[i] = i + firstDay;}return day;}2013-11-28

/**
* 获取前一个月的日期
*
* @return 前一个月的日期
*/
public static String getTodayBeforeMonth() {
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
Date currentTime = new Date();// 得到当前系统时间
long now = currentTime.getTime();// 返回自 1970 年 1 月 1 日 00:00:00 GMT
// 以来此Date 对象表示毫秒数
currentTime = new Date(now - 86400000 * 24);
long now1 = currentTime.getTime();
currentTime = new Date(now1 - 86400000 * 6);
String current = formatter.format(currentTime);
return current;
}

public static void main(String[] args) {
System.out.println(DateUtil.getTodayBeforeMonth());
}2013-11-28