解决ajax传过来的值后台接收不到的问题

function confirmCourseSystem(){
			var findAllTrainProgramNameId = $("#findAllTrainProgramNameId").val();
			if(findAllTrainProgramNameId==null || findAllTrainProgramNameId==""){
				window.alertx("请选择培训方案！");
				return false;
			}
			var courseSystemId = $('#CourseSystemList').val();
			alertx(courseSystemId);
			$.ajax({
				type: "POST",
				url: "${ctx}/teach/teachDistribute/getCourseSystemNameById",
				data: {
					"CourseSystemId": $('#CourseSystemList').val()
				},
				success:function(CourseSystemListName){
					$('#CourseSystemBody').html("");
					for(var i=0; i<CourseSystemListName.length; i++){
						$("#CourseSystemBody").append("<tr><td>"+CourseSystemListName[i] +"</td><td>课程体系</td><td>无</td></tr>");
					}
				},
				error:function(){
					alertx("error");
				}
			});
		}

//添加下发-确认选择，根据CourseSystemId获得CourseSystemName
	@ResponseBody
	@RequestMapping(value = "getCourseSystemNameById")
	public List<String> getCourseSystemNameById(@RequestParam(required = false) String CourseSystemId, HttpServletRequest request){
		logger.debug("==Evan==CourseSystemId: "+ CourseSystemId);
		logger.debug("==Evan==CourseSystemId2 :"+request.getParameter("CourseSystemId"));
		List<String> CourseSystemListName = new ArrayList<>();
		if(CourseSystemId==null || CourseSystemId.equals("")){
			CourseSystemListName = null;
		}else {
			String[] CourseSystemListId = CourseSystemId.split(",");
			for (String aCourseSystemListId : CourseSystemListId) {
				CourseSystemListName.add(resourceCoursesystemService.get(aCourseSystemListId).getCoursesystemName());
			}
		}
		return CourseSystemListName;
	}

	$.ajax({
				type: "POST",
				url: "${ctx}/teach/teachDistribute/getCourseSystemNameById",
				data: {
					"CourseSystemId": $('#CourseSystemList').val().toString()
				},
				success:function(CourseSystemListName){
					$('#CourseSystemBody').html("");
					for(var i=0; i<CourseSystemListName.length; i++){
						$("#CourseSystemBody").append("<tr><td>"+CourseSystemListName[i] +"</td><td>课程体系</td><td>无</td></tr>");
					}
				},
				error:function(){
					alertx("error");
				}
			});