获取近12月月份（含本月 格式：yyyy-MM）

public class Month12 {
    public static void main(String[] args) {
        Date today = new Date();
        //获取年的数据 yyyy
        SimpleDateFormat yyyy = new SimpleDateFormat("yyyy");
        //获取月的数据 MM
        SimpleDateFormat mm = new SimpleDateFormat("MM");
        String[] months = new String[12];
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, Integer.parseInt(yyyy.format(today)));
        cal.set(Calendar.MONTH, Integer.parseInt(mm.format(today)) - 1);
        cal.set(Calendar.DAY_OF_MONTH, 1);
        for (int i = 0; i < 12; i++) {
            //月份小于10 要拼接上0
            if(cal.get(Calendar.MONTH) + 1 < 10) {
                months[11 - i] = cal.get(Calendar.YEAR) + "-0" + (cal.get(Calendar.MONTH) + 1);
            }else {
                months[11 - i] = cal.get(Calendar.YEAR) + "-" + (cal.get(Calendar.MONTH) + 1);
            }
            //逐次往前推1个月
            cal.set(Calendar.MONTH, cal.get(Calendar.MONTH) - 1);
        }
        for (int i = 0; i < months.length; i++) {
            System.out.println(months[i]);
        }
    }
}