具有依赖项注入的View构造函数抛出NPE

Question

昨天，我将新的Vaadin 13 Spring应用程序推送到了服务器上。然后，当我在浏览器中打开我的应用程序时，登录名和仪表板视图运行良好，但是每当我尝试导航到具有构造函数并带有注入依赖项的View时，它将抛出NullPointerException。当我在本地运行该应用程序时，这永远不会发生！

我在这里全神贯注，不知道如何解决。我已经尝试了所有可能的变体，如何为视图构造函数注释注入。当我在本地运行它们时，它们都可以工作，而不能在我的服务器上运行。
-用@Inject或@Autowired注释整个构造函数
-使用@Autowired
注释每个注入的弹簧组件参数 -构造函数上根本没有注释

以下是异常消息和堆栈跟踪：

  

创建名称为“ path.to.ViewWithInjection”的bean时出错：通过构造函数实例化Bean失败；嵌套的异常是org.springframework.beans.BeanInstantiationException：无法实例化[path.to.ViewWithInjection]：构造方法引发了异常。嵌套的异常是java.lang.NullPointerException

org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:304)
org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:285)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1308)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1154)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:538)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:304)
com.vaadin.flow.spring.SpringInstantiator.getOrCreate(SpringInstantiator.java:88)
com.vaadin.flow.di.Instantiator.createRouteTarget(Instantiator.java:158)
com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.lambda$getRouteTarget$1(AbstractNavigationStateRenderer.java:116)
com.vaadin.flow.router.internal.AbstractNavigationStateRenderer$$Lambda$732.000000007C0ED790.get(Unknown Source)
java.util.Optional.orElseGet(Unknown Source)
com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.getRouteTarget(AbstractNavigationStateRenderer.java:115)
com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.handle(AbstractNavigationStateRenderer.java:167)
com.vaadin.flow.router.Router.handleNavigation(Router.java:221)
com.vaadin.flow.router.Router.navigate(Router.java:192)
com.vaadin.flow.router.Router.lambda$initializeUI$caa7783a$1(Router.java:93)
com.vaadin.flow.router.Router$$Lambda$717.000000007C0AEE30.onHistoryStateChange(Unknown Source)
com.vaadin.flow.server.communication.rpc.NavigationRpcHandler.handle(NavigationRpcHandler.java:66)
com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocationData(ServerRpcHandler.java:379)
com.vaadin.flow.server.communication.ServerRpcHandler.lambda$handleInvocations$0(ServerRpcHandler.java:368)
com.vaadin.flow.server.communication.ServerRpcHandler$$Lambda$994.00000000A093B760.accept(Unknown Source)
java.util.ArrayList.forEach(Unknown Source)
com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:368)
com.vaadin.flow.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:310)
com.vaadin.flow.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:89)
com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1545)
com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:227)
com.vaadin.flow.spring.SpringServlet.service(SpringServlet.java:65)
javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1255)
com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:743)
com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:440)
com.ibm.ws.webcontainer.filter.WebAppFilterChain.invokeTarget(WebAppFilterChain.java:182)
com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:78)
com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:996)
com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1134)
com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1005)
com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.dispatch(WebAppRequestDispatcher.java:1410)
com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:171)
org.springframework.web.servlet.mvc.ServletForwardingController.handleRequestInternal(ServletForwardingController.java:141)
org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:177)
org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:52)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1255)
com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:743)
com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:440)
com.ibm.ws.webcontainer.filter.WebAppFilterChain.invokeTarget(WebAppFilterChain.java:182)
com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:93)
org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:130)
org.springframework.boot.web.servlet.support.ErrorPageFilter.access$000(ErrorPageFilter.java:66)
org.springframework.boot.web.servlet.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:105)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:123)
com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:201)
com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:90)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:119)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:170)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:200)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:96)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:74)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:357)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:270)
com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:201)
com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:90)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:201)
com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:90)
com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:996)
com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1134)
com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1005)
com.ibm.ws.webcontainer.servlet.CacheServletWrapper.handleRequest(CacheServletWrapper.java:75)
com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:927)
com.ibm.ws.webcontainer.osgi.DynamicVirtualHost$2.run(DynamicVirtualHost.java:279)
com.ibm.ws.http.dispatcher.internal.channel.HttpDispatcherLink$TaskWrapper.run(HttpDispatcherLink.java:1023)
com.ibm.ws.http.dispatcher.internal.channel.HttpDispatcherLink.wrapHandlerAndExecute(HttpDispatcherLink.java:417)
com.ibm.ws.http.dispatcher.internal.channel.HttpDispatcherLink.ready(HttpDispatcherLink.java:376)
com.ibm.ws.http.channel.internal.inbound.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:532)
com.ibm.ws.http.channel.internal.inbound.HttpInboundLink.handleNewRequest(HttpInboundLink.java:466)
com.ibm.ws.http.channel.internal.inbound.HttpInboundLink.processRequest(HttpInboundLink.java:331)
com.ibm.ws.http.channel.internal.inbound.HttpICLReadCallback.complete(HttpICLReadCallback.java:70)
com.ibm.ws.tcpchannel.internal.WorkQueueManager.requestComplete(WorkQueueManager.java:501)
com.ibm.ws.tcpchannel.internal.WorkQueueManager.attemptIO(WorkQueueManager.java:571)
com.ibm.ws.tcpchannel.internal.WorkQueueManager.workerRun(WorkQueueManager.java:926)
com.ibm.ws.tcpchannel.internal.WorkQueueManager$Worker.run(WorkQueueManager.java:1015)
com.ibm.ws.threading.internal.ExecutorServiceImpl$RunnableWrapper.run(ExecutorServiceImpl.java:232)
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
java.lang.Thread.run(Unknown Source)

我正在使用cloudfoundry（cf-maven-plugin:1.1.3）推送到我的IBM Cloud，并使用自由（liberty-maven-plugin:2.4）在本地运行。
我的Vaadin版本是13.0.0.beta3，但使用12.0.7时会发生同样的情况。这是我第一次要在服务器上运行Vaadin Flow应用程序，所以我不是不是，这是由新的次要版本提升引起的。
使用的Springframework版本为5.1.2.RELEASE

当应用程序在服务器上运行时，如何使依赖注入在我的视图构造函数中起作用？

Answer 1

事实证明该错误根本不是由依赖项注入引起的。 NPE是由服务器设置的奇怪的区域设置引起的。我使用UI.getCurrent().getLocale()来获取语言环境，尽管我的服务器在德国，并且浏览器设置为ch-DE，但显然语言环境是en-US。由于我没有适用于美国的资源包，因此抛出了NPE。

在检查是否支持给定的语言环境后，如果捆绑软件不支持，则可以将UI语言环境设置为默认语言环境（由我定义）。