Hi again 
I managed Jetty to find the routing.
Now the page will be loaded in browser but not shown correctly. The page is shown completely empty, but when I take a look at the page’s source I see this:
<!doctype html><html lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><base href="."><meta name="viewport" content="width=device-width, initial-scale=1.0"><style type="text/css">body {height:100vh;width:100vw;margin:0;}.v-reconnect-dialog {position: absolute;top: 1em;right: 1em;border: 1px solid black;padding: 1em;z-index: 10000;}.v-system-error {color: red;background: white;position: absolute;top: 1em;right: 1em;border: 1px solid black;padding: 1em;z-index: 10000;pointer-events: auto;}</style><script type="text/javascript">//<![CDATA[
(function() { var apps = {}; var widgetsets = {}; var log; if (typeof console === undefined || !window.location.search.match(/[&?]
debug(&|$)/)) { /* If no console.log present, just use a no-op */ log = function() {}; } else if (typeof console.log === "function") { /* If it's a function, use it with apply */ log = function() { console.log.apply(console, arguments); }; } else { /* In IE, its a native function for which apply is not defined, but it works without a proper 'this' reference */ log = console.log; } var isWidgetsetLoaded = function(widgetset) { var className = widgetset.replace(/\./g, "_"); return (typeof window[className]
) != "undefined"; }; var loadWidgetset = function(url, widgetset) { if (widgetsets[widgetset]
) { return; } log("load widgetset", url, widgetset); setTimeout(function() { if (!isWidgetsetLoaded(widgetset)) { alert("Failed to load the widgetset: " + url); } }, 15000); var scriptTag = document.createElement('script'); scriptTag.setAttribute('type', 'text/javascript'); scriptTag.setAttribute('src', url); document.getElementsByTagName('head')[0]
.appendChild(scriptTag); widgetsets[widgetset]
= { pendingApps: [] }; }; var isInitializedInDom = function(appId) { var appDiv = document.getElementById(appId); if (!appDiv) { return false; } for ( var i = 0; i < appDiv.childElementCount; i++) { var className = appDiv.childNodes[i]
.className; /* If the app div contains a child with the class "v-app-loading" we have only received the HTML but not yet started the widget set (UIConnector removes the v-app-loading div). */ if (className && className.indexOf("v-app-loading") != -1) { return false; } } return true; }; /* * Needed for Testbench compatibility, but prevents any Vaadin 7 app from * bootstrapping unless the legacy vaadinBootstrap.js file is loaded before * this script. */ window.Vaadin = window.Vaadin || {}; window.Vaadin.Flow = window.Vaadin.Flow || { clients: {}, initApplication: function(appId, config) { var testbenchId = appId.replace(/-\d+$/, ''); if (apps[appId]
) { if (window.Vaadin && window.Vaadin.Flow && window.Vaadin.Flow.clients && window.Vaadin.Flow.clients[testbenchId]
&& window.Vaadin.Flow.clients[testbenchId]
.initializing) { throw "Application " + appId + " is already being initialized"; } if (isInitializedInDom(appId)) { throw "Application " + appId + " already initialized"; } } log("init application", appId, config); window.Vaadin.Flow.clients[testbenchId]
= { isActive: function() { return true; }, initializing: true }; var getConfig = function(name) { var value = config[name]
; return value; }; /* Export public data */ var app = { getConfig: getConfig }; apps[appId]
= app; if (!window.name) { window.name = appId + '-' + Math.random(); } var widgetset = "client"; widgetsets[widgetset]
= { pendingApps: [] }; if (widgetsets[widgetset]
.callback) { log("Starting from bootstrap", appId); widgetsets[widgetset]
.callback(appId); } else { log("Setting pending startup", appId); widgetsets[widgetset]
.pendingApps.push(appId); } return app; }, getAppIds: function() { var ids = [ ]
; for (var id in apps) { if (apps.hasOwnProperty(id)) { ids.push(id); } } return ids; }, getApp: function(appId) { return apps[appId]
; }, registerWidgetset: function(widgetset, callback) { log("Widgetset registered", widgetset); var ws = widgetsets[widgetset]
; if (ws && ws.pendingApps) { ws.callback = callback; for(var i = 0; i < ws.pendingApps.length; i++) { var appId = ws.pendingApps[i]
; log("Starting from register widgetset", appId); callback(appId); } ws.pendingApps = null; } } }; log('Flow bootstrap loaded'); if (typeof window.__gwtStatsEvent != 'function') {window.Vaadin.Flow.gwtStatsEvents = [];window.__gwtStatsEvent = function(event) {window.Vaadin.Flow.gwtStatsEvents.push(event); return true;};}; var uidl = {
"syncId": 0,
"clientId": 0,
"constants": {
"F8oCtNArLiI=": {
"event.shiftKey": false,
"event.metaKey": false,
"event.detail": false,
"event.ctrlKey": false,
"event.clientX": false,
"event.clientY": false,
"event.altKey": false,
"event.button": false,
"event.screenY": false,
"event.screenX": false
}
},
"changes": [
{
"node": 1,
"type": "put",
"key": "tag",
"feat": 0,
"value": "body"
},
{
"node": 1,
"type": "splice",
"feat": 2,
"index": 0,
"addNodes": [
54
]
},
[...]
skipped long list of nodes [...]
{
"node": 54,
"type": "put",
"key": "width",
"feat": 12,
"value": "100%"
}
],
"timings": [
0,
-1
],
"Vaadin-Security-Key": "f815b80a-a2bf-4479-8326-958b5f38a284",
"Vaadin-Push-ID": "b59f63c3-e2bc-4f94-9e3b-93478b3d7ce3"
}; var config = {
"frontendUrlEs6": "context://frontend/",
"frontendUrlEs5": "context://frontend/",
"versionInfo": {
"vaadinVersion": "1.0.4",
"atmosphereVersion": "2.4.24.vaadin1"
},
"sessExpMsg": {
"caption": null,
"message": null,
"url": null
},
"contextRootUrl": "./",
"debug": true,
"requestTiming": true,
"heartbeatInterval": 300,
"v-uiId": 0
}; config.uidl = uidl; window.Vaadin.Flow.initApplication("ROOT-2521314", config);})();//]]></script><script type="text/javascript" defer src="./VAADIN/static/client/client-CAF80B1F92BD4481C6D5EC01BC2D55AE.cache.js"></script><link rel="import" href="./frontend/bower_components/vaadin-button/src/vaadin-button.html"><link rel="import" href="./frontend/bower_components/vaadin-ordered-layout/src/vaadin-horizontal-layout.html"><link rel="import" href="./frontend/bower_components/vaadin-ordered-layout/src/vaadin-vertical-layout.html"><link rel="import" href="./frontend/bower_components/vaadin-lumo-styles/color.html"><link rel="import" href="./frontend/bower_components/vaadin-lumo-styles/typography.html"><link rel="import" href="./frontend/bower_components/vaadin-lumo-styles/sizing.html"><link rel="import" href="./frontend/bower_components/vaadin-lumo-styles/spacing.html"><link rel="import" href="./frontend/bower_components/vaadin-lumo-styles/style.html"><link rel="import" href="./frontend/bower_components/vaadin-lumo-styles/icons.html"><script id="_theme-header-injection">
function _inlineHeader(tag, content){
var customStyle = document.createElement(tag);
customStyle.innerHTML= content;
var firstScript=document.head.querySelector('script');
document.head.insertBefore(customStyle,firstScript);
}
_inlineHeader('custom-style','<style include="lumo-color lumo-typography"></style>');
document.head.removeChild(document.getElementById('_theme-header-injection'));
</script></head><body><noscript>You have to enable javascript in your browser to use this web site.</noscript></body></html>
Something seems to be missing that applies this code to a proper HTML rendering.