小编Var*_*lla的帖子

我正在尝试按照我在此处找到的说明将 Vaadin 项目连接到 MySQL 数据库：https: //dzone.com/articles/how-to-connect-a-mysql-database-to-a-vaadin-applic

我下载了文章中准备好的项目（也可以在这里找到： https: //github.com/Liskokuningas/databasemysqlexample）

然后，我在 MySQL Workbench 中创建了虚拟数据架构，并尝试通过 Windows 10 命令行运行该应用程序，如下所示： mvn clean install -U /*all is fine here, build is successful*/ 然后mvn spring-boot:run

然后我得到一个错误：

Followed by:
java.lang.RuntimeException: Unable to initialize com.vaadin.flow.spring.VaadinServletContextInitializer$VaadinAppShellContextListener
        at com.vaadin.flow.spring.VaadinServletContextInitializer$FailFastServletContextListener.contextInitialized(VaadinServletContextInitializer.java:192) ~[vaadin-spring-16.0.1.jar:na]
        at com.vaadin.flow.spring.VaadinServletContextInitializer$CompositeServletContextListener.lambda$contextInitialized$0(VaadinServletContextInitializer.java:209) ~[vaadin-spring-16.0.1.jar:na]
        at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) ~[na:na]
        at com.vaadin.flow.spring.VaadinServletContextInitializer$CompositeServletContextListener.contextInitialized(VaadinServletContextInitializer.java:209) ~[vaadin-spring-16.0.1.jar:na]
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4680) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5143) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
        at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
        at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
        at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841) …