Eclipselink忽略具有lambda表达式的实体类
我正在使用EclipseLink（2.5.1，也尝试过2.5.2-M1）构建一个java SE 8（oracle 1.8.0-b129）应用程序，并且有一个Entity类，它被EclipeLink忽略，尽管被正确注释并且在persistence.xml文件中引用。 日志显示没有提及类，没有为它生成模式，等等。使用实体给出’抽象模式类型未知’错误。
我想我终于找到了原因，并认为我会分享。 显然，EclipseLink不喜欢带有lambda表达式的类。 这是一个简单的类，可以重现问题：
@Entity public class LambdaEntity { @Id private Integer id; public void theLambda() { Arrays.asList(1, 2, 3).stream().filter(m -> m == 2); } } lambda表达式甚至不必使用持久属性，它在类中的简单存在就足够了。 有谁知道这会导致什么？ 我猜测EclipeLink会对生成的字节码产生影响，但我发现很奇怪它会默默地忽略该类。
如果您尝试在与其他实体的关联中使用此实体，EclipseLink将提供错误，指出实体未在persistence.xml文件中定义。 stacktrace的一部分：
Local Exception Stack: Exception [EclipseLink-30005] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException Exception Description: An exception was thrown while searching for persistence archives with ClassLoader: sun.misc.Launcher$AppClassLoader@3b9a45b3 Internal Exception: javax.persistence.PersistenceException: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.EntityManagerSetupException Exception Description: Predeployment of PersistenceUnit [hcm-test] failed. Internal Exception: Exception [EclipseLink-7250] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.ValidationException Exception Description: [class com.senior.hcm.domain.organization.Workstation] uses a non-entity [class com.senior.hcm.domain.auth.UserRole] as target entity in the relationship attribute [field roles]. at org.eclipse.persistence.exceptions.PersistenceUnitLoadingException.exceptionSearchingForPersistenceResources(PersistenceUnitLoadingException.java:127) at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactoryImpl(PersistenceProvider.java:107) at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:177) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54) Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.EntityManagerSetupException Exception Description: Predeployment of PersistenceUnit [hcm-test] failed. Internal Exception: Exception [EclipseLink-7250] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.ValidationException Exception Description: [class com.senior.hcm.domain.organization.Workstation] uses a non-entity [class com.senior.hcm.domain.auth.UserRole] as target entity in the relationship attribute [field roles]. at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.createPredeployFailedPersistenceException(EntityManagerSetupImpl.java:1954) at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:1945) at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.callPredeploy(JPAInitializer.java:98) at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactoryImpl(PersistenceProvider.java:96) ... 28 more Caused by: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.EntityManagerSetupException Exception Description: Predeployment of PersistenceUnit [hcm-test] failed. Internal Exception: Exception [EclipseLink-7250] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.ValidationException Exception Description: [class com.senior.hcm.domain.organization.Workstation] uses a non-entity [class com.senior.hcm.domain.auth.UserRole] as target entity in the relationship attribute [field roles]. at org.eclipse.persistence.exceptions.EntityManagerSetupException.predeployFailed(EntityManagerSetupException.java:230) ... 32 more Caused by: Exception [EclipseLink-7250] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.ValidationException Exception Description: [class com.senior.hcm.domain.organization.Workstation] uses a non-entity [class com.senior.hcm.domain.auth.UserRole] as target entity in the relationship attribute [field roles]. at org.eclipse.persistence.exceptions.ValidationException.nonEntityTargetInRelationship(ValidationException.java:1378) at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.RelationshipAccessor.getReferenceDescriptor(RelationshipAccessor.java:553) at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.RelationshipAccessor.getOwningMapping(RelationshipAccessor.java:469) at org.eclipse.persistence.internal.jpa.metadata.accessors.mappings.ManyToManyAccessor.process(ManyToManyAccessor.java:149) at org.eclipse.persistence.internal.jpa.metadata.MetadataProject.processNonOwningRelationshipAccessors(MetadataProject.java:1566) at org.eclipse.persistence.internal.jpa.metadata.MetadataProject.processStage3(MetadataProject.java:1855) at org.eclipse.persistence.internal.jpa.metadata.MetadataProcessor.processORMMetadata(MetadataProcessor.java:580) at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processORMetadata(PersistenceUnitProcessor.java:585) at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:1869) ... 30 more
正如Michael Jess（谢谢:) :)所建议的，这里是这个问题的bug报告的链接。 不幸的是，我还没有时间来测试那里已经完成的工作，但它看起来很有希望。 看来，这个问题不应该存在太长时间。