我在我的頁(yè)面上進(jìn)行了簡(jiǎn)單的登錄。登錄后，我正在顯示來(lái)自服務(wù)器的數(shù)據(jù)，這只是在刷新頁(yè)面一次后顯示。在我收到錯(cuò)誤 500 之前：GET http://localhost:8080/getDesktop 500angular.js:14800 Possibly unhandled rejection: ...我的 AngularJS 代碼如下：var app = angular.module("myApp", []);app.controller("myCtrl", function($scope, $http, $window, $timeout){//Username$scope.user  = "";//Desktop$scope.storage = [];//Get username$http.get("/loggeduser", {transformResponse: function(response){        return JSON.stringify(response);    }}).then(function(response) {    $scope.user = response.data.substring(1, response.data.length-1);});//Show Desktop    $http.get("/getDesktop").then(function(response){    for(var i = 0; i<response.data.length; i++){           $scope.storage[i] = {name: response.data[i]};       }                  return;   });});后端：//Returns Desktop@GetMapping("/getDesktop")public ArrayList<String> getDesktop() throws Exception {    ArrayList<String> itemNames = new ArrayList<>();    if(kdxF.getUser() != null) {        itemNames = kdxF.showDesktop();          // Just a function to return the Elements in an ArrayList if Strings        // If user is logged in    }else {        throw new Exception("Not logged in!");    }    return itemNames;}我收到消息“未登錄”