我从这个论坛上了一个登录Web应用程序的课程进行测试。
我使用Vaadin设计器来制作单页Web应用程序。用户应该登录并将转移到我与设计师一起创建的网站。目前，Web应用程序没有Java连接，我的唯一目标是从登录转移到MainView页面。
今天我又试了一次，它不再起作用了。 我在 Java 方面什么也没做，只是扩展了设计器文件。
package com.example;
import com.vaadin.flow.component.button.Button;
import com.vaadin.flow.component.login.AbstractLogin;
import com.vaadin.flow.component.login.LoginForm;
import com.vaadin.flow.component.notification.Notification;
import com.vaadin.flow.component.orderedlayout.VerticalLayout;
import com.vaadin.flow.router.Route;
import com.vaadin.flow.server.PWA;
import com.vaadin.flow.server.VaadinSession;
import java.util.Objects;
import java.util.Optional;
/**
* The main view contains a button and a click listener.
*/
@Route ( "" )
@PWA ( name = "Project Base for Vaadin", shortName = "Project Base" )
public class MainView extends VerticalLayout
{
public MainView ( )
{
this.display();
}
private void display ( )
{
if ( Objects.isNull( VaadinSession.getCurrent().getAttribute( User.class ) ) )
{
this.removeAll();
this.add( this.makeLoginForm() );
} else
{ // Else we have a User, so must be authenticated.
this.removeAll();
this.add( new MyContentView() );
}
}
private LoginForm makeLoginForm ( )
{
Authenticator authenticator = new Authenticator();
LoginForm component = new LoginForm();
component.addLoginListener( ( AbstractLogin.LoginEvent loginEvent ) -> {
Optional < User > user = authenticator.authenticate( loginEvent.getUsername() , loginEvent.getPassword() );
if ( user.isPresent() )
{
VaadinSession.getCurrent().setAttribute( User.class , user.get() );
this.display();
} else
{
component.setError( true );
}
} );
return component;
}
package com.example;
import com.vaadin.flow.component.accordion.Accordion;
import com.vaadin.flow.component.button.Button;
import com.vaadin.flow.component.datepicker.DatePicker;
import com.vaadin.flow.component.html.Label;
import com.vaadin.flow.component.polymertemplate.Id;
import com.vaadin.flow.templatemodel.TemplateModel;
import com.vaadin.flow.component.Tag;
import com.vaadin.flow.component.dependency.JsModule;
import com.vaadin.flow.component.polymertemplate.PolymerTemplate;
/**
* A Designer generated component for the my-content-view template.
*
* Designer will add and remove fields with @Id mappings but
* does not overwrite or otherwise change this file.
*/
@Tag("my-content-view")
@JsModule("./my-content-view.js")
public class MyContentView extends PolymerTemplate<MyContentView.MyContentViewModel> {
@Id("vaadinAccordion")
private Accordion vaadinAccordion;
@Id("label")
private Label label;
@Id("label1")
private Label label1;
@Id("birthday")
private DatePicker birthday;
@Id("vaadinButton")
private Button vaadinButton;
/**
* Creates a new MyContentView.
*/
public MyContentView() {
// You can initialize any data required for the connected UI components here.
}
/**
* This model binds properties between MyContentView and my-content-view
*/
public interface MyContentViewModel extends TemplateModel {
// Add setters and getters for template properties here.
}
}
这是错误 登录后按摩并更新网站
There was an exception while trying to navigate to '' with the exception message 'Error creating bean with name 'com.example.MainView': Instantiation of bean failed;
nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.example.MainView]: Constructor threw exception;
nested exception is java.lang.IllegalStateException: There is no element with id='vaadinAccordion' in the template file './my-content-view.js'. Cannot map it using @Id'
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.example.MainView': Instantiation of bean failed;
nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.example.MainView]: Constructor threw exception;
nested exception is java.lang.IllegalStateException: There is no element with id='vaadinAccordion' in the template file './my-content-view.js'. Cannot map it using @Id
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1320)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1214)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:307)
at com.vaadin.flow.spring.SpringInstantiator.getOrCreate(SpringInstantiator.java:117)
at com.vaadin.flow.di.Instantiator.createRouteTarget(Instantiator.java:160)
at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.lambda$getRouteTarget$1(AbstractNavigationStateRenderer.java:133)
at java.base/java.util.Optional.orElseGet(Optional.java:369)
at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.getRouteTarget(AbstractNavigationStateRenderer.java:132)
at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.sendBeforeEnterEventAndPopulateChain(AbstractNavigationStateRenderer.java:498)
at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.createChainIfEmptyAndExecuteBeforeEnterNavigation(AbstractNavigationStateRenderer.java:477)
at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.handle(AbstractNavigationStateRenderer.java:228)
at com.vaadin.flow.router.Router.handleNavigation(Router.java:249)
at com.vaadin.flow.router.Router.navigate(Router.java:220)
at com.vaadin.flow.router.Router.navigate(Router.java:186)
at com.vaadin.flow.router.Router.initializeUI(Router.java:93)
at com.vaadin.flow.server.BootstrapHandler.createAndInitUI(BootstrapHandler.java:1516)
at com.vaadin.flow.server.BootstrapHandler.synchronizedHandleRequest(BootstrapHandler.java:472)
at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1545)
at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:247)
at com.vaadin.flow.spring.SpringServlet.service(SpringServlet.java:120)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:712)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:459)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:352)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:312)
at org.springframework.web.servlet.mvc.ServletForwardingController.handleRequestInternal(ServletForwardingController.java:141)
at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:177)
at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:52)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1579)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.example.MainView]: Constructor threw exception; nested exception is java.lang.IllegalStateException: There is no element with id='vaadinAccordion' in the template file './my-content-view.js'. Cannot map it using @Id
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:213)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1312)
... 72 more
Caused by: java.lang.IllegalStateException: There is no element with id='vaadinAccordion' in the template file './my-content-view.js'. Cannot map it using @Id
at com.vaadin.flow.component.polymertemplate.IdCollector.collectedInjectedId(IdCollector.java:106)
at com.vaadin.flow.component.polymertemplate.IdCollector.lambda$collectInjectedIds$1(IdCollector.java:78)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
at com.vaadin.flow.component.polymertemplate.IdCollector.collectInjectedIds(IdCollector.java:78)
at com.vaadin.flow.component.polymertemplate.IdCollector.collectInjectedIds(IdCollector.java:67)
at com.vaadin.flow.component.polymertemplate.TemplateDataAnalyzer.parseTemplate(TemplateDataAnalyzer.java:215)
at com.vaadin.flow.component.polymertemplate.TemplateInitializer.<init>(TemplateInitializer.java:91)
at com.vaadin.flow.component.polymertemplate.PolymerTemplate.<init>(PolymerTemplate.java:88)
at com.vaadin.flow.component.polymertemplate.PolymerTemplate.<init>(PolymerTemplate.java:103)
at com.example.MyContentView.<init>(MyContentView.java:38)
at com.example.MainView.display(MainView.java:38)
at com.example.MainView.<init>(MainView.java:26)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:200)
... 74 more
import {html, PolymerElement} from '@polymer/polymer/polymer-element.js';
import '@vaadin/vaadin-button/src/vaadin-button.js';
import '@vaadin/vaadin-charts/src/vaadin-chart.js';
import '@vaadin/vaadin-ordered-layout/src/vaadin-vertical-layout.js';
import '@vaadin/vaadin-ordered-layout/src/vaadin-horizontal-layout.js';
import '@vaadin/vaadin-date-picker/src/vaadin-date-picker.js';
import '@vaadin/vaadin-accordion/src/vaadin-accordion.js';
class MyContentView extends PolymerElement {
static get template() {
return html`
<style include="shared-styles">
:host {
display: block;
height: 100%;
}
</style>
<vaadin-horizontal-layout style="width: 100%; height: 100%;">
<vaadin-vertical-layout class="sidebar" style="flex-basis: calc(7*var(--lumo-size-s)); flex-shrink: 0; background-color: var(--lumo-contrast-5pct);">
<vaadin-vertical-layout theme="spacing" style="flex-grow: 1; align-self: stretch;">
<vaadin-vertical-layout theme="spacing" style="flex-grow: 1; align-self: stretch;">
<vaadin-button>
Button
</vaadin-button>
</vaadin-vertical-layout>
<vaadin-vertical-layout theme="spacing" style="flex-grow: 1; align-self: stretch;">
<vaadin-button theme="primary">
Primary
</vaadin-button>
</vaadin-vertical-layout>
</vaadin-vertical-layout>
<vaadin-vertical-layout theme="spacing" style="flex-grow: 1; align-self: stretch;">
<vaadin-button id="vaadinButton">
Button
</vaadin-button>
<vaadin-accordion></vaadin-accordion>
</vaadin-vertical-layout>
</vaadin-vertical-layout>
<vaadin-vertical-layout class="content" style="flex-grow: 1; flex-shrink: 1; flex-basis: auto;">
<vaadin-vertical-layout theme="spacing" style="align-self: stretch; height: 20%;">
<vaadin-chart type="pie" title="Browser market shares in January, 2018" tooltip="">
<vaadin-chart-series title="Brands" values="[["Chrome",61.41],["Internet Explorer",11.84],["Firefox",10.85],["Edge",4.67],["Safari",4.18],["Sogou Explorer",1.64],["Opera",1.6],["QQ",1.2],["Other",2.61]]"></vaadin-chart-series>
</vaadin-chart>
</vaadin-vertical-layout>
<vaadin-vertical-layout theme="spacing" style="align-self: stretch; flex-grow: 1;">
<vaadin-horizontal-layout theme="spacing" style="flex-grow: 1; height: 100%; align-self: stretch;">
<vaadin-vertical-layout theme="spacing" style="width: 30%;">
<vaadin-vertical-layout theme="margin" style="height: 50%; align-self: stretch; width: 100%; padding: var(--lumo-space-m);">
<label id="label1">Neuigkeiten - Letzter Monat</label>
</vaadin-vertical-layout>
<vaadin-vertical-layout theme="margin" style="height: 50%; align-self: stretch; flex-grow: 0; width: 100%; padding: var(--lumo-space-m);"></vaadin-vertical-layout>
</vaadin-vertical-layout>
<vaadin-vertical-layout theme="spacing" style="width: 100%;">
<vaadin-vertical-layout style="width: 100%; height: 50%;">
<label id="label">Meine Kurse</label>
</vaadin-vertical-layout>
<vaadin-vertical-layout style="width: 100%; height: 50%;"></vaadin-vertical-layout>
</vaadin-vertical-layout>
<vaadin-vertical-layout theme="spacing" style="width: 30%;">
<vaadin-vertical-layout theme="spacing" style="width: 100%; height: 50%; padding: var(--lumo-space-m);">
<label>Mail</label>
</vaadin-vertical-layout>
<vaadin-vertical-layout theme="spacing" style="width: 100%; height: 50%; padding: var(--lumo-space-m);">
<vaadin-date-picker label="Datum" placeholder="Pick a date" id="birthday">
Datum
</vaadin-date-picker>
</vaadin-vertical-layout>
</vaadin-vertical-layout>
</vaadin-horizontal-layout>
</vaadin-vertical-layout>
</vaadin-vertical-layout>
</vaadin-horizontal-layout>
`;
}
static get is() {
return 'my-content-view';
}
static get properties() {
return {
// Declare your properties here.
};
}
}
customElements.define(MyContentView.is, MyContentView);
正如错误所述：
There is no element with id='vaadinAccordion' in the template file
设计文件的"HTML"包含一个手风琴标签，但没有id属性：
<vaadin-accordion></vaadin-accordion>