Java 带复合键的EclipseLink JPA@ElementCollection映射--删除时出错

我有一个实体，其地图字段映射为嵌入集合：

@Entity
public class PhysicalTp implements Serializable {
    ...
    @Id @Column(name="PTP_ID")
    private long id;

    @ElementCollection(fetch=FetchType.LAZY)
    @CollectionTable(name="IUT_PTP_TRANSMISSION_PARAMETER",
        joinColumns={ @JoinColumn(name="TMP_PTP_ID", referencedColumnName="PTP_ID") })
    @Column(name="TMP_VALUE")
    private Map<TransmissionParameter,String> transmissionParameters;
    ...
}

CatLayerRate是一个简单的字典实体：

@Entity
public class CatLayerRate implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id @Column(name="CLR_ID")
    private long id;

    @Column(name="CLR_DESC")
    private String desc;

    @Basic(optional=false)
    @Column(name="CLR_NAME", nullable=false)
    private String name;
    ... (hashCode, equals, getters, setters)
}

除了删除实体之外，所有映射都可以正常工作。当我尝试删除任何PhysicalTp实例时，Eclipselink抛出一个异常：

Exception Description: A NullPointerException was thrown while extracting a value from the instance variable [null] in the object [PhysicalTp].
Internal Exception: java.lang.NullPointerException
Mapping: org.eclipse.persistence.mappings.AggregateObjectMapping[null]
Descriptor: RelationalDescriptor(PhysicalTp --> [DatabaseTable(IUT_PHYSICAL_TP)])

另外，我不能将TransmissionParameter映射为@OneToMany实体，因为它被各种实体使用，并且对于每个实体，它都必须映射到自己的表

日食2.5.1

Salu2， 安东

UPD：与其他实体复制的完整stacktrace

javax.persistence.RollbackException: Exception [EclipseLink-69] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: A NullPointerException was thrown while extracting a value from the instance variable [null] in the object [eclipselink.bugs.TestEmbeddedMapKeyBug$MainEntity].
Internal Exception: java.lang.NullPointerException
Mapping: org.eclipse.persistence.mappings.AggregateObjectMapping[null]
Descriptor: RelationalDescriptor(eclipselink.bugs.TestEmbeddedMapKeyBug$MainEntity --> [DatabaseTable(TESTEMBEDDEDMAPKEYBUG$MAINENTITY)])
    at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:157)
    at eclipselink.bugs.TestEmbeddedMapKeyBug.testEmbeddedMapKeyBug(TestEmbeddedMapKeyBug.java:202)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: Exception [EclipseLink-69] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: A NullPointerException was thrown while extracting a value from the instance variable [null] in the object [eclipselink.bugs.TestEmbeddedMapKeyBug$MainEntity].
Internal Exception: java.lang.NullPointerException
Mapping: org.eclipse.persistence.mappings.AggregateObjectMapping[null]
Descriptor: RelationalDescriptor(eclipselink.bugs.TestEmbeddedMapKeyBug$MainEntity --> [DatabaseTable(TESTEMBEDDEDMAPKEYBUG$MAINENTITY)])
    at org.eclipse.persistence.exceptions.DescriptorException.nullPointerWhileGettingValueThruInstanceVariableAccessor(DescriptorException.java:1277)
    at org.eclipse.persistence.internal.descriptors.InstanceVariableAttributeAccessor.getAttributeValueFromObject(InstanceVariableAttributeAccessor.java:88)
    at org.eclipse.persistence.mappings.DatabaseMapping.getAttributeValueFromObject(DatabaseMapping.java:630)
    at org.eclipse.persistence.mappings.DatabaseMapping.getRealAttributeValueFromObject(DatabaseMapping.java:786)
    at org.eclipse.persistence.mappings.AggregateObjectMapping.earlyPreDelete(AggregateObjectMapping.java:1043)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1412)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithChangeSet(UnitOfWorkImpl.java:1531)
    at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.commitRootUnitOfWork(RepeatableWriteUnitOfWork.java:277)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitAndResume(UnitOfWorkImpl.java:1169)
    at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:132)
    ... 25 more
Caused by: java.lang.NullPointerException
    at org.eclipse.persistence.internal.descriptors.InstanceVariableAttributeAccessor.getAttributeValueFromObject(InstanceVariableAttributeAccessor.java:76)
    ... 33 more

---

您的映射中是否有空值，或者要删除的对象上的映射本身是否为空值？您可以发布堆栈跟踪以显示哪些代码可能会命中NPE吗？不，没有空值。操作persist/read/update运行良好，只是删除失败。这似乎是日食中的一只虫子。如果我删除@Embeddeble对象中的@ManyToOne并将字段更改为Long LayerRaid，则删除工作正常。我找到了解决方法：使用DELETE查询而不是em.remove。

javax.persistence.RollbackException: Exception [EclipseLink-69] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: A NullPointerException was thrown while extracting a value from the instance variable [null] in the object [eclipselink.bugs.TestEmbeddedMapKeyBug$MainEntity].
Internal Exception: java.lang.NullPointerException
Mapping: org.eclipse.persistence.mappings.AggregateObjectMapping[null]
Descriptor: RelationalDescriptor(eclipselink.bugs.TestEmbeddedMapKeyBug$MainEntity --> [DatabaseTable(TESTEMBEDDEDMAPKEYBUG$MAINENTITY)])
    at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:157)
    at eclipselink.bugs.TestEmbeddedMapKeyBug.testEmbeddedMapKeyBug(TestEmbeddedMapKeyBug.java:202)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: Exception [EclipseLink-69] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: A NullPointerException was thrown while extracting a value from the instance variable [null] in the object [eclipselink.bugs.TestEmbeddedMapKeyBug$MainEntity].
Internal Exception: java.lang.NullPointerException
Mapping: org.eclipse.persistence.mappings.AggregateObjectMapping[null]
Descriptor: RelationalDescriptor(eclipselink.bugs.TestEmbeddedMapKeyBug$MainEntity --> [DatabaseTable(TESTEMBEDDEDMAPKEYBUG$MAINENTITY)])
    at org.eclipse.persistence.exceptions.DescriptorException.nullPointerWhileGettingValueThruInstanceVariableAccessor(DescriptorException.java:1277)
    at org.eclipse.persistence.internal.descriptors.InstanceVariableAttributeAccessor.getAttributeValueFromObject(InstanceVariableAttributeAccessor.java:88)
    at org.eclipse.persistence.mappings.DatabaseMapping.getAttributeValueFromObject(DatabaseMapping.java:630)
    at org.eclipse.persistence.mappings.DatabaseMapping.getRealAttributeValueFromObject(DatabaseMapping.java:786)
    at org.eclipse.persistence.mappings.AggregateObjectMapping.earlyPreDelete(AggregateObjectMapping.java:1043)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1412)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithChangeSet(UnitOfWorkImpl.java:1531)
    at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.commitRootUnitOfWork(RepeatableWriteUnitOfWork.java:277)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitAndResume(UnitOfWorkImpl.java:1169)
    at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:132)
    ... 25 more
Caused by: java.lang.NullPointerException
    at org.eclipse.persistence.internal.descriptors.InstanceVariableAttributeAccessor.getAttributeValueFromObject(InstanceVariableAttributeAccessor.java:76)
    ... 33 more