导航至'customers'页面时出现Spring依赖注入异常

这个问题很典型，就是Spring容器找不到你要自动装配的CrudEntityPresenter Bean，导致CustomersView没法通过构造函数注入依赖启动。核心异常就是这句：

org.springframework.beans.factory.NoSuchBeanDefinitionException：找不到类型为'com.nfg.crm.ui.crud.CrudEntityPresenter'的合格Bean：期望至少有1个符合自动装配候选条件的Bean。

给你几个排查和解决的方向：

• 给CrudEntityPresenter添加Spring组件注解：如果这个类是你自己写的，要在类上加上@Component（通用组件）、@Service（业务逻辑类）这类注解，这样Spring在启动扫描的时候才会把它纳入容器管理，生成对应的Bean实例。
• 确认组件扫描范围覆盖目标包：检查你的Spring Boot主启动类上的@SpringBootApplication注解，默认它只会扫描主类所在包及其子包。如果CrudEntityPresenter所在的com.nfg.crm.ui.crud不在这个范围内，就得手动添加@ComponentScan来指定扫描的包，比如：

  @SpringBootApplication
  @ComponentScan(basePackages = {"com.nfg.crm.ui"})
  public class YourCrmApplication {
      public static void main(String[] args) {
          SpringApplication.run(YourCrmApplication.class, args);
      }
  }
  

• 如果是接口，确保有实现类并注解：要是CrudEntityPresenter是接口类型，那你必须有一个实现这个接口的类，并且给实现类加上组件注解，Spring才能找到具体的Bean来注入。
• 检查是否有配置类漏掉了Bean定义：如果是通过@Configuration类里的@Bean方法来定义这个Bean的，要确认那个配置类被Spring扫描到，并且@Bean方法正确返回了CrudEntityPresenter的实例。

附上完整的异常栈信息方便你参考：

尝试导航至'customers'页面时发生异常，异常信息如下：
'创建名称为'com.nfg.crm.ui.views.customers.CustomersView'的Bean时出错：通过构造函数参数0表达的依赖不满足；嵌套异常为org.springframework.beans.factory.NoSuchBeanDefinitionException：找不到类型为'com.nfg.crm.ui.crud.CrudEntityPresenter'的合格Bean：期望至少有1个符合自动装配候选条件的Bean。依赖注解：{}' 
org.springframework.beans.factory.UnsatisfiedDependencyException：创建名称为'com.nfg.crm.ui.views.customers.CustomersView'的Bean时出错：通过构造函数参数0表达的依赖不满足；嵌套异常为org.springframework.beans.factory.NoSuchBeanDefinitionException：找不到类型为'com.nfg.crm.ui.crud.CrudEntityPresenter'的合格Bean：期望至少有1个符合自动装配候选条件的Bean。依赖注解：{} 
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:729) 
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:192) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1270) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1127) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:304) 
at com.vaadin.flow.spring.SpringInstantiator.getOrCreate(SpringInstantiator.java:86) 
at com.vaadin.flow.di.Instantiator.createRouteTarget(Instantiator.java:157) 
at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.lambda$getRouteTarget$1(AbstractNavigationStateRenderer.java:114) 
at java.util.Optional.orElseGet(Optional.java:267) 
at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.getRouteTarget(AbstractNavigationStateRenderer.java:113) 
at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.handle(AbstractNavigationStateRenderer.java:165) 
at com.vaadin.flow.router.Router.handleNavigation(Router.java:178) 
at com.vaadin.flow.router.Router.navigate(Router.java:150) 
at com.vaadin.flow.router.Router.initializeUI(Router.java:91) 
at com.vaadin.flow.component.UI.lambda$doInit$0(UI.java:205) 
at java.util.Optional.ifPresent(Optional.java:159) 
at com.vaadin.flow.component.UI.doInit(UI.java:205) 
at com.vaadin.flow.server.BootstrapHandler.createAndInitUI(BootstrapHandler.java:988) 
at com.vaadin.flow.server.BootstrapHandler.synchronizedHandleRequest(BootstrapHandler.java:388) 
at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40) 
at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1541) 
at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:345) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) 
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:728) 
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:470) 
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:356) 
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:316) 
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:991) 
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) 
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978) 
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:870) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687) 
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:855) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) 
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Applic...

内容的提问来源于stack exchange，提问作者Quân Nguyễn Hồng