easyui commobox省市区县三级联动

1.前端代码
<div class="col-6 f-group">
                <label class="col-4 left_red">
                    省名称
                </label>
                <div class="col-8">
                    <input type="text" id="province" name="province"
                           readonly hidden="hidden"/>
                    <input type="text" id="province_name" panelHeight="100" name="province_name"
                           dataType="Require"
                           msg="省名称不能为空"/>
                </div>
            </div>
            <div class="col-6 f-group">
                <label class="col-4 left_red">
                    市名称
                </label>
                <div class="col-8">
                    <input type="text" id="city_code" name="city_code"
                           readonly hidden="hidden"/>
                    <input type="text" id="city_name" panelHeight="100" name="city_name"
                           dataType="Require"
                           msg="市名称不能为空"/>
                </div>
            </div>

            <div class="col-6 f-group">
                <label class="col-4 left_red">
                    区县名称
                </label>
                <div class="col-8">
                    <input type="text" id="county_code" name="county_code"
                           readonly hidden="hidden"/>
                    <input type="text" id="county_name" panelHeight="100" name="county_name" dataType="Require"
                           msg="区县名称不能为空"/>
                </div>
            </div>

2.javascript代码
/**easyui省市区县三级联动开始**/

    /**省级**/
    $(function () {
        $("#province_name").combobox({
            valueField: 'name',//值字段
            url: "${base}/baseinfo/district/getAllProvince?region=province",
            textField: 'name',//显示字段
            method: 'POST',
            editable: false,//不可编辑只能选择
            value: '  请选择  ',
            onSelect: function (obj) {
                $("#city_name").combobox("setValue", '  请选择  ');//清除市列表
                $("#county_name").combobox("setValue", '');//清除区县列表
                $("#city_code").val('');//清除市编码
                $("#county_code").val('');//清除区县编码

                $('#province').val(obj.code);

                $('#city_name').combobox('reload', "${base}/baseinfo/district/getAllCity?region=city&&id=" + obj.id);
            }
        });
        /**市级**/
        $("#city_name").combobox({
            valueField: 'name',//值字段
            textField: 'name',//显示字段
            editable: false,//不可编辑只能选择
            value: ' ',
            onSelect: function (obj) {
                $("#county_name").combobox("setValue", '  请选择  ');//清除区县列表
                $("#county_code").val('');//清除区县编码
                $('#city_code').val(obj.code);
                //$('#city').combobox('clear');
                $('#county_name').combobox('reload', "${base}/baseinfo/district/getAllCounty?region=county&&id=" + obj.id);
            }
        });

        //生成随机数
        function RndNum(n) {
            var rnd = "";
            for (var i = 0; i < n; i++)
                rnd += Math.floor(Math.random() * 10);
            return rnd;
        }

        /**区县级**/
        $("#county_name").combobox({
            valueField: 'name',//值字段
            textField: 'name',//显示字段
            editable: false,//不可编辑只能选择
            value: ' ',
            onSelect: function (obj) {
                $('#county_code').val(obj.code);
                var x = obj.code + RndNum(2);
                $('#street_code').val(x);
                var y = x + RndNum(2);
                $('#community_code').val(y);
                $('#residentia_code').val(y + RndNum(2));
            }
        });
    });

    /**easyui省市区县三级联动结束**/

3.控制层代码
/**获得省级信息**/
@RequestMapping(value = "getAllProvince", method = RequestMethod.POST)
@ResponseBody
public List<DistrictDomain> getAllProvince(String region) throws Exception {
    DistrictDomain domain = new DistrictDomain();
    domain.setRegion(region);
    List<DistrictDomain> list=Collections.emptyList();
    list = districtService.query(domain);
    return  list;
}
/**获得市级信息**/
@RequestMapping(value = "getAllCity", method=RequestMethod.POST)
@ResponseBody
public List<DistrictDomain> getAllProvince(@Param("region") String region,@Param("id") Long id) throws Exception {
    DistrictDomain domain = new DistrictDomain();
    domain.setId(id);
    domain.setRegion(region);
    List<DistrictDomain> list=Collections.emptyList();
    list = districtService.query(domain);
    return  list;
}
/**获得区县信息**/
@RequestMapping(value = "getAllCounty", method=RequestMethod.POST)
@ResponseBody
public List<DistrictDomain> getAllCounty(@Param("region") String region,@Param("id") Long id) throws Exception {
    DistrictDomain domain = new DistrictDomain();
    domain.setId(id);
    domain.setRegion(region);
    List<DistrictDomain> list=Collections.emptyList();
    list = districtService.query(domain);
    return  list;
}