TomEE JPA MySql 配置 "An invalid Lifecycle transition was attempted"

Question

我是 Java EE 的新手，花了一些时间学习它。在这个错误上花了几个小时，找不到完全相似的问题，在同一门课程中排除了一名学生的 udemy 问答，但老师无法帮助学生。

教程是在 MySQL 上使用 TomEE 和 JPA 教授持久性。

我正在使用 Eclipse: 面向 Web 开发人员的 Eclipse Java EE IDE。版本：2018-09 (4.9.0)

TomEE 版本： Tomcat v9.0 服务器

使用 JRE 的 TomEE: jdk-12.0.1

项目Java构建路径-->模块路径-->执行环境： JavaSE-10 (jdk-12.0.1)

Java 编译器： 使用来自执行环境 JavaSE-10

的合规性

lib TomEE 文件夹中的实际 MySql 连接器（尝试了几个）： mysql-连接器-java-8.0.17.jar

这是我的tomee.xml

<tomee>
    <Resource id="connessioneCorsoWeb" type="DataSource">
        JdbcDriver          com.mysql.jdbc.Driver
        JdbcUrl             jdbc:Mysql://127.0.0.1:3306/corso_java_web?useUnicode=true&amp;useJDBCCompliantTimezoneShift=true&amp;useLegacyDatetimeCode=false&amp;serverTimezone=UTC
        UserName            root
        Password            admin
    </Resource>
</tomee>

这是persistence.xml

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="1.0">
    <persistence-unit name="corsoWebPersistence">
        <jta-data-source>connessioneCorsoWeb</jta-data-source>
        <properties>
            <property name="openejb.jpa.auto-scan" value="true"/>
        </properties>
    </persistence-unit>
</persistence>

启动应用程序时的控制台消息对我没有帮助

INFO: Undeploying app: D:\Shared\Studio\Java EE Developer - La guida completa\apache-tomee-8.0.0-M3-plume\apache-tomee-plume-8.0.0-M3\webapps\corso-web Aug 16, 2019 12:11:31 PM jdk.internal.reflect.NativeMethodAccessorImpl invoke SEVERE: Error destroying child org.apache.catalina.LifecycleException: An invalid Lifecycle transition was attempted ([before_destroy]) for component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web]] in state [STARTING_PREP] at org.apache.catalina.util.LifecycleBase.invalidTransition(LifecycleBase.java:430) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:316) at org.apache.catalina.core.ContainerBase.removeChild(ContainerBase.java:814) ...

我可以看什么更深入？

编辑：

删除 persistence.xml 服务器启动。

添加 persistence.xml 只有几行：

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="1.0">
</persistence>

服务器启动。

把persistence.xml改成这样就好了：

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="1.0">
    <persistence-unit>
    </persistence-unit>
</persistence>

服务器出现故障。

这是对当前控制台的更详尽的摘录：

... Aug 18, 2019 3:21:18 PM org.apache.tomee.catalina.TomcatWebAppBuilder startInternal SEVERE: Unable to deploy collapsed ear in war StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web] java.lang.NullPointerException at org.apache.openejb.util.LinkResolver.resolve(LinkResolver.java:55) at org.apache.openejb.util.LinkResolver.add(LinkResolver.java:37) at org.apache.openejb.util.LinkResolver.add(LinkResolver.java:33) at org.apache.openejb.config.AutoConfig.resolvePersistenceRefs(AutoConfig.java:223) at org.apache.openejb.config.AutoConfig.deploy(AutoConfig.java:197) at org.apache.openejb.config.ConfigurationFactory$Chain.deploy(ConfigurationFactory.java:420) at org.apache.openejb.config.ConfigurationFactory.configureApplication(ConfigurationFactory.java:1033) at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1286) at org.apache.tomee.catalina.TomcatWebAppBuilder.configureStart(TomcatWebAppBuilder.java:1130) at org.apache.tomee.catalina.GlobalListenerSupport.lifecycleEvent(GlobalListenerSupport.java:134) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5048) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:932) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.startup.Catalina.start(Catalina.java:633) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:567) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:344) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:475)

Aug 18, 2019 3:21:18 PM jdk.internal.reflect.NativeMethodAccessorImpl invoke SEVERE: Error destroying child org.apache.catalina.LifecycleException: An invalid Lifecycle transition was attempted ([before_destroy]) for component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web]] in state [STARTING_PREP] at org.apache.catalina.util.LifecycleBase.invalidTransition(LifecycleBase.java:430) at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:316) at org.apache.catalina.core.ContainerBase.removeChild(ContainerBase.java:814) at org.apache.tomee.catalina.TomcatWebAppBuilder.undeploy(TomcatWebAppBuilder.java:1656) at org.apache.tomee.catalina.TomcatWebAppBuilder.undeploy(TomcatWebAppBuilder.java:1636) at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1317) at org.apache.tomee.catalina.TomcatWebAppBuilder.configureStart(TomcatWebAppBuilder.java:1130) at org.apache.tomee.catalina.GlobalListenerSupport.lifecycleEvent(GlobalListenerSupport.java:134) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5048) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:932) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.startup.Catalina.start(Catalina.java:633) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:567) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:344) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:475)

Aug 18, 2019 3:21:18 PM jdk.internal.reflect.NativeMethodAccessorImpl invoke SEVERE: A child container failed during start java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web]] at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:932) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.startup.Catalina.start(Catalina.java:633) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:567) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:344) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:475) Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web]] at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) ... 21 more Caused by: org.apache.tomee.catalina.TomEERuntimeException: java.lang.NullPointerException at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1320) at org.apache.tomee.catalina.TomcatWebAppBuilder.configureStart(TomcatWebAppBuilder.java:1130) at org.apache.tomee.catalina.GlobalListenerSupport.lifecycleEvent(GlobalListenerSupport.java:134) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5048) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ... 27 more Caused by: java.lang.NullPointerException at org.apache.openejb.util.LinkResolver.resolve(LinkResolver.java:55) at org.apache.openejb.util.LinkResolver.add(LinkResolver.java:37) at org.apache.openejb.util.LinkResolver.add(LinkResolver.java:33) at org.apache.openejb.config.AutoConfig.resolvePersistenceRefs(AutoConfig.java:223) at org.apache.openejb.config.AutoConfig.deploy(AutoConfig.java:197) at org.apache.openejb.config.ConfigurationFactory$Chain.deploy(ConfigurationFactory.java:420) at org.apache.openejb.config.ConfigurationFactory.configureApplication(ConfigurationFactory.java:1033) at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1286) ... 32 more

Aug 18, 2019 3:21:18 PM jdk.internal.reflect.NativeMethodAccessorImpl invoke SEVERE: A child container failed during start java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:932) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.startup.Catalina.start(Catalina.java:633) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:567) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:344) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:475) Caused by: org.apache.catalina.LifecycleException: A child container failed during start at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:921) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) ... 13 more Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web]] at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) ... 21 more Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web]] at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) ... 21 more Caused by: org.apache.tomee.catalina.TomEERuntimeException: java.lang.NullPointerException at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1320) at org.apache.tomee.catalina.TomcatWebAppBuilder.configureStart(TomcatWebAppBuilder.java:1130) at org.apache.tomee.catalina.GlobalListenerSupport.lifecycleEvent(GlobalListenerSupport.java:134) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5048) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ... 27 more Caused by: java.lang.NullPointerException at org.apache.openejb.util.LinkResolver.resolve(LinkResolver.java:55) at org.apache.openejb.util.LinkResolver.add(LinkResolver.java:37) at org.apache.openejb.util.LinkResolver.add(LinkResolver.java:33) at org.apache.openejb.config.AutoConfig.resolvePersistenceRefs(AutoConfig.java:223) at org.apache.openejb.config.AutoConfig.deploy(AutoConfig.java:197) at org.apache.openejb.config.ConfigurationFactory$Chain.deploy(ConfigurationFactory.java:420) at org.apache.openejb.config.ConfigurationFactory.configureApplication(ConfigurationFactory.java:1033) at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1286) ... 32 more

Aug 18, 2019 3:21:18 PM jdk.internal.reflect.NativeMethodAccessorImpl invoke SEVERE: The required Server component failed to start so Tomcat is unable to start. org.apache.catalina.LifecycleException: A child container failed during start at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:921) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:932) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.startup.Catalina.start(Catalina.java:633) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:567) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:344) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:475) Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) ... 13 more Caused by: org.apache.catalina.LifecycleException: A child container failed during start at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:921) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) ... 13 more Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web]] at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) ... 21 more Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/corso-web]] at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) ... 21 more Caused by: org.apache.tomee.catalina.TomEERuntimeException: java.lang.NullPointerException at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1320) at org.apache.tomee.catalina.TomcatWebAppBuilder.configureStart(TomcatWebAppBuilder.java:1130) at org.apache.tomee.catalina.GlobalListenerSupport.lifecycleEvent(GlobalListenerSupport.java:134) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5048) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ... 27 more Caused by: java.lang.NullPointerException at org.apache.openejb.util.LinkResolver.resolve(LinkResolver.java:55) at org.apache.openejb.util.LinkResolver.add(LinkResolver.java:37) at org.apache.openejb.util.LinkResolver.add(LinkResolver.java:33) at org.apache.openejb.config.AutoConfig.resolvePersistenceRefs(AutoConfig.java:223) at org.apache.openejb.config.AutoConfig.deploy(AutoConfig.java:197) at org.apache.openejb.config.ConfigurationFactory$Chain.deploy(ConfigurationFactory.java:420) at org.apache.openejb.config.ConfigurationFactory.configureApplication(ConfigurationFactory.java:1033) at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1286) ... 32 more

Aug 18, 2019 3:21:18 PM jdk.internal.reflect.DelegatingMethodAccessorImpl invoke INFO: Pausing ProtocolHandler ["http-nio-8080"] Aug 18, 2019 3:21:18 PM jdk.internal.reflect.DelegatingMethodAccessorImpl invoke INFO: Pausing ProtocolHandler ["ajp-nio-8009"] Aug 18, 2019 3:21:18 PM jdk.internal.reflect.DelegatingMethodAccessorImpl invoke INFO: Stopping service [Catalina] Aug 18, 2019 3:21:18 PM org.apache.openejb.server.SimpleServiceManager stop INFO: Stopping server services Aug 18, 2019 3:21:18 PM org.apache.openejb.assembler.classic.Assembler destroyApplication INFO: Undeploying app: D:\Shared\Studio\Java EE Developer - La guida completa\apache-tomee-8.0.0-M3-plume\apache-tomee-plume-8.0.0-M3\webapps\ROOT Aug 18, 2019 3:21:18 PM org.apache.openejb.assembler.classic.Assembler doResourceDestruction INFO: Closing DataSource: connessioneCorsoWeb Aug 18, 2019 3:21:18 PM jdk.internal.reflect.DelegatingMethodAccessorImpl invoke INFO: Destroying ProtocolHandler ["http-nio-8080"] Aug 18, 2019 3:21:18 PM jdk.internal.reflect.DelegatingMethodAccessorImpl invoke INFO: Destroying ProtocolHandler ["ajp-nio-8009"]

如有任何想法，我们将不胜感激。

Answer 1

试试这个：

<?xml version="1.0" encoding="UTF-8"?>
<persistence
    xmlns="http://xmlns.jcp.org/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"
    version="2.1">
    <persistence-unit name="corsoWebPersistence">
        <jta-data-source>connessioneCorsoWeb</jta-data-source>
        <properties>
            <property
                name="openejb.jpa.auto-scan"
                value="true" />
        </properties>
    </persistence-unit>
</persistence>

Answer 2

最后我解决了，说的很清楚：在 Udemy 课程中被使用 Tomcat v8.0 服务器 (apache-tomee-7.0.4) 相反，我正在使用 Tomcat v9.0 服务器 (apache-tomee-8.0.0-M3-plume)

现在使用旧版本不需要，但是使用 tomee-8.0.0 有必要在 Project Facets 中设置 JPA（当检查 JPA 屏幕警报以配置它时），或在 JPA 项目属性中设置。

我已经测试了两个 tomee 版本，现在都可以使用了。

这是我的 Tomcat v9.0 服务器 (apache-tomee-8.0.0-M3-plume)

中的 JPA 配置屏幕

TomEE JPA MySql 配置 "An invalid Lifecycle transition was attempted"

TomEE JPA MySql Configuration "An invalid Lifecycle transition was attempted"

mysql

eclipse

jpa

apache-tomee

jakarta-ee