我有一个复杂的数据模型，该模型除其他外还使用抽象类。使用AutomaticPojoCodec将数据模型对象写入MongoDB可以正常工作，但是当尝试再次从MongoDB读取数据模型对象时，显示以下错误：
org.bson.codecs.configuration.CodecConfigurationException: An exception occurred when decoding using the AutomaticPojoCodec.
Decoding into a 'ReqIF' failed with the following exception:
Failed to decode 'coreContent'. Failed to decode 'reqIF_content'. Failed to decode 'datatypes'. Failed to decode 'datatypeDefinitions'. An exception occurred when decoding using the AutomaticPojoCodec.
Decoding into a 'DatatypeDefinitionTag' failed with the following exception:
null
A custom Codec or PojoCodec may need to be explicitly configured and registered to handle this type.
A custom Codec or PojoCodec may need to be explicitly configured and registered to handle this type.
at org.bson.codecs.pojo.AutomaticPojoCodec.decode(AutomaticPojoCodec.java:40)
at com.mongodb.operation.CommandResultArrayCodec.decode(CommandResultArrayCodec.java:52)
at com.mongodb.operation.CommandResultDocumentCodec.readValue(CommandResultDocumentCodec.java:60)
at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:84)
at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:41)
at org.bson.codecs.configuration.LazyCodec.decode(LazyCodec.java:47)
at org.bson.codecs.BsonDocumentCodec.readValue(BsonDocumentCodec.java:101)
at com.mongodb.operation.CommandResultDocumentCodec.readValue(CommandResultDocumentCodec.java:63)
at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:84)
at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:41)
at com.mongodb.connection.ReplyMessage.<init>(ReplyMessage.java:50)
at com.mongodb.connection.CommandProtocol.getResponseDocument(CommandProtocol.java:132)
at com.mongodb.connection.CommandProtocol.execute(CommandProtocol.java:111)
at com.mongodb.connection.DefaultServer$DefaultServerProtocolExecutor.execute(DefaultServer.java:159)
at com.mongodb.connection.DefaultServerConnection.executeProtocol(DefaultServerConnection.java:289)
at com.mongodb.connection.DefaultServerConnection.command(DefaultServerConnection.java:176)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:216)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:207)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:113)
at com.mongodb.operation.FindOperation$1.call(FindOperation.java:715)
at com.mongodb.operation.FindOperation$1.call(FindOperation.java:709)
at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:433)
at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:406)
at com.mongodb.operation.FindOperation.execute(FindOperation.java:709)
at com.mongodb.operation.FindOperation.execute(FindOperation.java:81)
at com.mongodb.Mongo.execute(Mongo.java:810)
at com.mongodb.Mongo$2.execute(Mongo.java:797)
at com.mongodb.OperationIterable.iterator(OperationIterable.java:47)
at com.mongodb.FindIterableImpl.iterator(FindIterableImpl.java:200)
at com.mongodb.FindIterableImpl.iterator(FindIterableImpl.java:37)
at io.cesonia.camelot.knight.reqIF.mongoDB.ReqIF_MongoDB_Reader.findByAddress(ReqIF_MongoDB_Reader.java:43)
at io.cesonia.camelot.knight.reqIF.mongoDB.ReqIF_MongoDB_Reader.readReqIF_DataFromMongoDB(ReqIF_MongoDB_Reader.java:29)
at io.cesonia.camelot.knight.reqIF.mongoDB.ReqIF_MongoDB_ReaderTest.readReqIF_DataFromMongoDB_shouldReturnReqIF_dataObject(ReqIF_MongoDB_ReaderTest.java:49)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:686)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:205)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:201)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:137)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:71)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
at java.util.ArrayList.forEach(Unknown Source)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
at java.util.ArrayList.forEach(Unknown Source)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:248)
at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$5(DefaultLauncher.java:211)
at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:226)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:199)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:141)
at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:542)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:770)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:464)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:210)
Caused by: org.bson.codecs.configuration.CodecConfigurationException: Failed to decode 'coreContent'. Failed to decode 'reqIF_content'. Failed to decode 'datatypes'. Failed to decode 'datatypeDefinitions'. An exception occurred when decoding using the AutomaticPojoCodec.
Decoding into a 'DatatypeDefinitionTag' failed with the following exception:
null
A custom Codec or PojoCodec may need to be explicitly configured and registered to handle this type.
at org.bson.codecs.pojo.PojoCodecImpl.decodePropertyModel(PojoCodecImpl.java:173)
at org.bson.codecs.pojo.PojoCodecImpl.decodeProperties(PojoCodecImpl.java:149)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:103)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:107)
at org.bson.codecs.pojo.AutomaticPojoCodec.decode(AutomaticPojoCodec.java:37)
... 97 more
Caused by: org.bson.codecs.configuration.CodecConfigurationException: Failed to decode 'reqIF_content'. Failed to decode 'datatypes'. Failed to decode 'datatypeDefinitions'. An exception occurred when decoding using the AutomaticPojoCodec.
Decoding into a 'DatatypeDefinitionTag' failed with the following exception:
null
A custom Codec or PojoCodec may need to be explicitly configured and registered to handle this type.
at org.bson.codecs.pojo.PojoCodecImpl.decodePropertyModel(PojoCodecImpl.java:173)
at org.bson.codecs.pojo.PojoCodecImpl.decodeProperties(PojoCodecImpl.java:149)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:103)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:107)
at org.bson.codecs.pojo.LazyPojoCodec.decode(LazyPojoCodec.java:55)
at org.bson.codecs.DecoderContext.decodeWithChildContext(DecoderContext.java:93)
at org.bson.codecs.pojo.PojoCodecImpl.decodePropertyModel(PojoCodecImpl.java:165)
... 101 more
Caused by: org.bson.codecs.configuration.CodecConfigurationException: Failed to decode 'datatypes'. Failed to decode 'datatypeDefinitions'. An exception occurred when decoding using the AutomaticPojoCodec.
Decoding into a 'DatatypeDefinitionTag' failed with the following exception:
null
A custom Codec or PojoCodec may need to be explicitly configured and registered to handle this type.
at org.bson.codecs.pojo.PojoCodecImpl.decodePropertyModel(PojoCodecImpl.java:173)
at org.bson.codecs.pojo.PojoCodecImpl.decodeProperties(PojoCodecImpl.java:149)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:103)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:107)
at org.bson.codecs.pojo.LazyPojoCodec.decode(LazyPojoCodec.java:55)
at org.bson.codecs.DecoderContext.decodeWithChildContext(DecoderContext.java:93)
at org.bson.codecs.pojo.PojoCodecImpl.decodePropertyModel(PojoCodecImpl.java:165)
... 107 more
Caused by: org.bson.codecs.configuration.CodecConfigurationException: Failed to decode 'datatypeDefinitions'. An exception occurred when decoding using the AutomaticPojoCodec.
Decoding into a 'DatatypeDefinitionTag' failed with the following exception:
null
A custom Codec or PojoCodec may need to be explicitly configured and registered to handle this type.
at org.bson.codecs.pojo.PojoCodecImpl.decodePropertyModel(PojoCodecImpl.java:173)
at org.bson.codecs.pojo.PojoCodecImpl.decodeProperties(PojoCodecImpl.java:149)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:103)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:107)
at org.bson.codecs.pojo.LazyPojoCodec.decode(LazyPojoCodec.java:55)
at org.bson.codecs.DecoderContext.decodeWithChildContext(DecoderContext.java:93)
at org.bson.codecs.pojo.PojoCodecImpl.decodePropertyModel(PojoCodecImpl.java:165)
... 113 more
Caused by: org.bson.codecs.configuration.CodecConfigurationException: An exception occurred when decoding using the AutomaticPojoCodec.
Decoding into a 'DatatypeDefinitionTag' failed with the following exception:
null
A custom Codec or PojoCodec may need to be explicitly configured and registered to handle this type.
at org.bson.codecs.pojo.AutomaticPojoCodec.decode(AutomaticPojoCodec.java:40)
at org.bson.codecs.pojo.CollectionCodec.decode(CollectionCodec.java:53)
at org.bson.codecs.pojo.CollectionCodec.decode(CollectionCodec.java:30)
at org.bson.codecs.DecoderContext.decodeWithChildContext(DecoderContext.java:93)
at org.bson.codecs.pojo.PojoCodecImpl.decodePropertyModel(PojoCodecImpl.java:165)
... 119 more
Caused by: org.bson.codecs.configuration.CodecConfigurationException
at org.bson.codecs.pojo.CreatorExecutable.getInstance(CreatorExecutable.java:89)
at org.bson.codecs.pojo.InstanceCreatorImpl.<init>(InstanceCreatorImpl.java:40)
at org.bson.codecs.pojo.InstanceCreatorFactoryImpl.create(InstanceCreatorFactoryImpl.java:28)
at org.bson.codecs.pojo.ClassModel.getInstanceCreator(ClassModel.java:70)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:102)
at org.bson.codecs.pojo.PojoCodecImpl.decode(PojoCodecImpl.java:107)
at org.bson.codecs.pojo.AutomaticPojoCodec.decode(AutomaticPojoCodec.java:37)
... 123 more
Caused by: java.lang.InstantiationException
at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.bson.codecs.pojo.CreatorExecutable.getInstance(CreatorExecutable.java:84)
... 129 more
我相信此错误的相关内容如下：
Failed to decode 'coreContent'.
Failed to decode 'reqIF_content'.
Failed to decode 'datatypes'.
Failed to decode 'datatypeDefinitions'.
An exception occurred when decoding using the AutomaticPojoCodec.
Decoding into a 'DatatypeDefinitionTag' failed with the following exception:
[…]
Caused by: java.lang.InstantiationException
我认为发生这种情况是因为“ DatatypeDefinitionTag”是一个抽象类，因此不能也不应将其初始化。它用于存储有关数据类型定义的数据，因此可以包含可变数量的DatatypeDefinitionString，DatatypeDefinitionDate，DatatypeDefinitionInt等...对象。
在我的数据类型类中，错误变量datatypeDefinitions的定义如下：
public List<DatatypeDefinitionTag> datatypeDefinitions;
...并且该变量充满了看起来像这样的对象：
public class DatatypeDefinitionString extends DatatypeDefinitionTag{[...]}
public class DatatypeDefinitionInt extends DatatypeDefinitionTag{[...]}
public class DatatypeDefinitionDate extends DatatypeDefinitionTag{[...]}
我有理由确定这是导致错误的原因，因为如果我从数据对象中删除数据类型，该错误将不再出现。但是，这自然不是可行的解决方案。
我的问题归结为两件事：
我终于让它工作了。
秘密在于升级到org.mongodb:mongodb-driver:3.6.0或更高版本，从而解决了此问题。之后，只需添加以下注释即可：
@BsonDiscriminator
public abstract class DatatypeDefinitionTag extends IdentifiableTag {