$.getJSON JQuery-IllegalStateException

Question

谁能帮帮我吗？我使用JQuery$.getJSON()根据选定的下拉列表（category）加载一个下拉列表（subcategories）的内容。

由于某种原因我得到了一个IllegalStateException。提前谢谢你。

<script>
    $(document)
            .ready(
                    function() {

                        // reload subcategories when changing category
                        $('#categories').change(loadSubcategories);

                    });

    // load the subcategories based on selected category
    function loadSubcategories() {
        $.getJSON('findSubcategoriesForCategory.html', {
            categoryId : $('#categories').val(),
            ajax : 'true'
        }, function(data) {
            var html = '<option value="">Select Subcategory</option>';
            var len = data.length;
            for ( var i = 0; i < len; i++) {
                html += '<option value="' + data[i].id + '">' + data[i].name
                        + '</option>';
            }
            html += '</option>';

            $('#subcategories').html(html);

        });
    }
</script>

@RequestMapping(value = "findSubcategoriesForCategory", method = RequestMethod.GET)
public @ResponseBody
List<Subcategory> findSubcategoriesForCategory(
        @RequestParam(value = "categoryId", required = true) String categoryId) {

    List<Subcategory> returnList = new ArrayList<Subcategory>();

    try {
        returnList = categoryService
                .findSubcategoriesForCategory(categoryId);
    } catch (Exception e) {
        LOGGER.error("An Error occured when Finding sub-categories for category id: " + categoryId);
    }

    return returnList;

}

Answer 1

这是来自您的Web服务器的响应。前端不涉及Java。：）