public static String getStatetime() throws ParseException{

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

Calendar c = Calendar.getInstance();

c.add(Calendar.DATE, - 7);

Date monday = c.getTime();

String preMonday = sdf.format(monday);

return preMonday;

}

 

来自：http://blog.sina.com.cn/s/blog_48fd85de0100gphn.html