AJAX JSON 乱码

网上下了一个JS、功能是把FORM里的内容序列化为JSON、用AJAX方式提交到后台
JS比较小巧
(function ($) {
    var formJson = {};
    var currentForm = null;

    $.fn.form_serialize = function () {
        currentForm = $(this);
        formJson = {};
        var doms = currentForm.find('[name]');
        $.each(doms, function (index, dom) {
            var domName = $(dom).attr('name');
            if (!formJson[domName]) {
                formJson[domName] = { Name: domName, Type: $(dom).attr('type'), Doms: currentForm.find('[name=' + domName + ']') };
            }
        });
        return getResult();
    };

    var getResult = function () {
        var d = {
            toJson: function () {
                var data = {};
                $.each(formJson, function (key, json) {
                    data[key] = getVal(json);
                });
                return data;
            },
        };
        return d.toJson();
    }

    var getVal = function (json) {
        var methods = {
            getDefaultVal: function (dom) {
                return $(dom).val();
            },
            getSelectVal: function (dom) {
                var val = '';
                var selectType = $(dom).attr('type');
                if (selectType == 'select-multiple') {
                    var items = $(dom).val();
                    if (items == null) return '';
                    for (var i = 0; i < items.length; i++) {
                        val += i == 0 ? items[i] : (',' + items[i]);
                    }
                    return val;
                } else {
                    return $(dom).val();
                }
            },
            getRadioVal: function (dom) {
                return $(dom).attr('checked') ? $(dom).val() : null;
            },
            getCheckBoxVal: function (dom) {
                return methods.getRadioVal(dom);
            }
        };

        var dispacher = function (type, dom) {
            switch (type) {
                case 'text':
                case 'password':
                case 'hidden':
                case 'textarea':
                    return methods.getDefaultVal(dom);
                case 'select-one':
                case 'select-multiple':
                    return methods.getSelectVal(dom);
                case 'radio':
                    return methods.getRadioVal(dom);
                case 'checkbox':
                    return methods.getCheckBoxVal(dom);
                default:
                    return '';
            }
        };

        var domType = json.Type;
        var doms = $(json.Doms);
        var count = doms.length;
        if (count > 1) {
            var val = '';
            var index = 0;
            for (var i = 0; i < count; i++) {
                var v = dispacher(domType, doms.eq(i));
                if (v == '' || v == null || v == undefined)
                    continue;
                val += index++ == 0 ? dispacher(domType, doms.eq(i)) : (',' + dispacher(domType, doms.eq(i)));
            }
            return val;
        } else {
            return dispacher(domType, doms);
        }
    };
})(jQuery);
AJAX调用为:
var formjson=$("#main").form_serialize();
$.getJSON(actionnm,formjson, function(data)
到后台后FORM中输入的中文就乱码了
JSP、ACTION应该没问题、因为我改为FORM的SUBMIT提交就没问题
JS中的这段我改了一下
  getDefaultVal: function (dom) {
   eturn encodeURI(encodeURI($(dom).val()));
   },
还是乱码
不知应怎么改?
应改不是那段JS的问题
我改成
var formjson={"wfclient.cname":"字字"};
$.getJSON(actionnm,formjson, function(data)
也不行