Spring Boot 1.4.1 可运行 jar javax.persistence.PersistenceException：无法解析持久性单元根 URL

Question

我们有一个 Spring Boot 1.4.1 应用程序，当我们创建可运行的 jar 并尝试运行它时，我们会得到以下堆栈跟踪：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'xxxEntityManager' defined in class path resource [xxx/web/config/XxxConfig.class]: Invocation of init method failed; nested exception is javax.persistence.Persistenc
eException: Unable to resolve persistence unit root URL
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1583) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1076) ~[spring-context-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:851) ~[spring-context-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541) ~[spring-context-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.1.RELEASE.jar!/:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.1.RELEASE.jar!/:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.1.RELEASE.jar!/:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.1.RELEASE.jar!/:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.1.RELEASE.jar!/:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.1.RELEASE.jar!/:1.4.1.RELEASE]
        at xxx.App.main(App.java:48) [classes!/:0.0.1-SNAPSHOT]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_05]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_05]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_05]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_05]
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) [NES-Web-0.0.1-SNAPSHOT-exec.jar:0.0.1-SNAPSHOT]
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) [NES-Web-0.0.1-SNAPSHOT-exec.jar:0.0.1-SNAPSHOT]
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) [NES-Web-0.0.1-SNAPSHOT-exec.jar:0.0.1-SNAPSHOT]
        at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:58) [NES-Web-0.0.1-SNAPSHOT-exec.jar:0.0.1-SNAPSHOT]
Caused by: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
        at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.determineDefaultPersistenceUnitRootUrl(DefaultPersistenceUnitManager.java:605) ~[spring-orm-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.preparePersistenceUnitInfos(DefaultPersistenceUnitManager.java:445) ~[spring-orm-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.afterPropertiesSet(DefaultPersistenceUnitManager.java:426) ~[spring-orm-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:325) ~[spring-orm-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:373) ~[spring-orm-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:362) ~[spring-orm-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1642) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1579) ~[spring-beans-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        ... 24 common frames omitted
Caused by: java.io.FileNotFoundException: class path resource [] cannot be resolved to URL because it does not exist
        at org.springframework.core.io.ClassPathResource.getURL(ClassPathResource.java:187) ~[spring-core-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.determineDefaultPersistenceUnitRootUrl(DefaultPersistenceUnitManager.java:602) ~[spring-orm-4.3.3.RELEASE.jar!/:4.3.3.RELEASE]
        ... 31 common frames omitted

我们也发现了这个问题https://github.com/spring-projects/spring-boot/issues/6635，但是根据它，这应该在Spring Boot 1.4.1中修复

注意：我们的模型类中没有注释，我们使用 hbm.xml 文件进行映射。但是，我们使用 Spring Data JPA 存储库。

Answer 1

我在使用 maven-jar-plugin 构建 jar 时遇到了同样的错误，但是像下面这样构建 jar 可以正常工作：

    <build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
     </plugins>
    </build>

Answer 2

根据我在此处阅读的说明 (https://github.com/spring-projects/spring-boot/issues/6983#issuecomment-249981782)，我设法通过执行以下操作来解决此问题：

1. 我创建了 META-INF/orm.xml 文件并将其放在 src/main/resources 文件夹中。文件的内容可以在这个链接https://github.com/spring-projects/spring-data-jpa/blob/master/src/test/resources/META-INF/orm.xml 找到（你实际上并不需要 persistence-unit-metadata、named-query 和 entity标签，只需一个带有根 entity-mappings 标签的空 XML 就足够了）。

2. 在配置 LocalContainerEntityManagerFactoryBean bean 时，我需要调用 setPersistenceUnitRootLocation 方法并将位置设置为 classpath:META-INF/orm.xml

这个解决方法解决了我在运行 fat jar 时遇到的问题。但是，通过实施此解决方法，我产生了另一个问题 - 我无法从 IDE 运行应用程序，因此我必须根据我是在运行 jar 还是从某个指标来实现持久性单元根位置的某种条件设置IDE。

Answer 3

您可能受到this regression 的影响。问题中提供了一种解决方法。请尝试一下并等待1.4.2.RELEASE。对不起:(