java 获取本周第一天

/*

* 取本周7天的第一天（周一的日期）

*/

public static String getNowWeekBegin() {

int mondayPlus;

Calendar cd = Calendar.getInstance();

// 获得今天是一周的第几天，星期日是第一天，星期二是第二天......

int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK) - 1; // 因为按中国礼拜一作为第一天所以这里减1

if (dayOfWeek == 1) {

mondayPlus = 0;

} else {

mondayPlus = 1 - dayOfWeek;

}

GregorianCalendar currentDate = new GregorianCalendar();

currentDate.add(GregorianCalendar.DATE, mondayPlus);

Date monday = currentDate.getTime();

DateFormat df = DateFormat.getDateInstance();

String preMonday = df.format(monday);

return preMonday + " 00:00:00";

}