向页面setAttribute年份、12个月份

private static final ArrayList<HashMap<String, Object>> YEAR_LIST;
private static final List<HashMap<String, String>> MONTH_LIST;
private static String currentMonth;
static {
    //start 这段代码用于向页面setAttribute年份以及月份
    //获取当前年份及前2年
    Calendar cal = Calendar.getInstance();
    int currYear = cal.get(Calendar.YEAR);
    // List<HashMap<String, Object>> yearList = new ArrayList<>();
    YEAR_LIST = new ArrayList<>();
    // for(int i = currYear-2; currYear >= i; i++){
    for(int i = currYear; i > currYear-3; i--){
        HashMap<String, Object> map = new HashMap<>();
        map.put("year",i);
        YEAR_LIST.add(map);
    }

    //获取当前月份
    currentMonth = String.valueOf(cal.get(Calendar.MONTH)+1);
    if (currentMonth.length() < 2)
        currentMonth = "0" + currentMonth;
    //获取12个月份
    int currMonth = 0;
    MONTH_LIST = new ArrayList<>();
    HashMap<String, String> maps = null;
    for (int y = currMonth+12; y > currMonth; y--) {
        maps = new HashMap<>();
        if (y < 10) {
            maps.put("month", "0"+y);
        } else {
            maps.put("month", ""+y);
        }
        MONTH_LIST.add(maps);
    }
    //将12个月份中remove当前月份 其中list有个size为0的map
    Collection<String> coll = maps.values();
    while (coll.contains(currentMonth)) {
        coll.remove(currentMonth);
    }
    //remove size为0的map
    Iterator<HashMap<String, String>> iter = MONTH_LIST.iterator();
    while (iter.hasNext()) {
        HashMap<String, String> map = iter.next();
        if (map.size()==0)
            iter.remove();
    }
    //end
}

request.setAttribute("yearList", YEAR_LIST);
request.setAttribute("monthList", MONTH_LIST);
request.setAttribute("currentMonth", currentMonth);

效果如下：