SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Calendar c = Calendar.getInstance(); //过去七天
c.setTime(new Date());
c.add(Calendar.DATE, - 7);
Date d = c.getTime();
String day = format.format(d);
System.out.println("过去七天:"+day); //过去一月
c.setTime(new Date());
c.add(Calendar.MONTH, -1);
Date m = c.getTime();
String mon = format.format(m);
System.out.println("过去一个月:"+mon); //过去三个月
c.setTime(new Date());
c.add(Calendar.MONTH, -3);
Date m3 = c.getTime();
String mon3 = format.format(m3);
System.out.println("过去三个月:"+mon3); //过去一年
c.setTime(new Date());
c.add(Calendar.YEAR, -1);
Date y = c.getTime();
String year = format.format(y);
System.out.println("过去一年:"+year);