java获取上一周、上一月、上一年的时间

        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Calendar c = Calendar.getInstance();
        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);

        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Calendar c = Calendar.getInstance();
        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);
        
        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);

        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Calendar c = Calendar.getInstance();
        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);

        SimpleDateFormat format  = new SimpleDateFormat("YYYY-MM-dd ");
        Calendar c = Calendar.getInstance();
        c.set(Calendar.DAY_OF_WEEK,Calendar.MONDAY);
        String weekStart = format.format(c.getTime())+" 00:00:00";
        System.out.println(weekStart);
        Calendar ca = Calendar.getInstance();
        ca.setFirstDayOfWeek(Calendar.MONDAY);
        ca.set(Calendar.DAY_OF_WEEK, ca.getFirstDayOfWeek() + 6); // Sunday
        String weekEnd = format.format(ca.getTime())+" 23:59:59";
        System.out.println(weekEnd);

        SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd");
        Calendar c = Calendar.getInstance();
        c.set(Calendar.DAY_OF_MONTH,1);//设置为1号,当前日期既为本月第一天
        String monthStart = format.format(c.getTime())+" 00:00:00";
        System.out.println(monthStart);
        Calendar ca = Calendar.getInstance();
        ca.set(Calendar.DAY_OF_MONTH, ca.getActualMaximum(Calendar.DAY_OF_MONTH));
        String monthEnd = format.format(ca.getTime())+" 23:59:59";
        System.out.println(monthEnd);

      SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        Calendar c = Calendar.getInstance();
        c.set(c.get(Calendar.YEAR) ,0, 1);//开始时间日期
        String yearStart = format.format(c.getTime())+" 00:00:00";
        System.out.println(yearStart);
        Calendar ca = Calendar.getInstance();
        ca.set(ca.get(Calendar.YEAR) ,11, ca.getActualMaximum(Calendar.DAY_OF_MONTH));//结束日期
        String yearEnd = format.format(ca.getTime())+" 23:59:59";
        System.out.println(yearEnd);