处理DataTable的后台公共方法

获取页面DataTable的排序和分页信息

private Map<String, Object> getOrderAndLimit(HttpServletRequest request){
    Map<String, Object> param = new HashMap<String, Object>();
    String start = request.getParameter("start");
    String length = request.getParameter("length");
    String order_colum_index = request.getParameter("order[0][column]");
    String order_dir = request.getParameter("order[0][dir]");
    String _order = "";
    if(order_colum_index != null && order_dir != null){
        _order = request.getParameter("columns[" + Integer.parseInt(order_colum_index) + "][data]") + " " + order_dir;
    }
    Map<String, Object> _limit = new HashMap<String, Object>();
    _limit.put("_pstart", start);
    _limit.put("_psize", length);
    param.put("_order", _order);
    param.put("_limit", _limit);
    return param;
}

转化Ajax请求数据为DataTable可接受的Json字符串形式

private String GetResponseString(HttpServletRequest request, int recordsTotal, int recordsFiltered, List data){
    Map<String, Object> map = new HashMap<String, Object>();
    map.put("recordsTotal", recordsTotal);
    map.put("recordsFiltered", recordsFiltered);
    map.put("draw", Integer.parseInt(request.getParameter("draw")));
    map.put("data", data);
    try {
        return JsonUtils.convertToString(map);
    } catch (IOException e) {
        e.printStackTrace();
        return "";
    }
}
private String GetResponseString(HttpServletRequest request, int recordsFiltered, List data){
    return GetResponseString(request, recordsFiltered, recordsFiltered, data);
}