【发布时间】：2021-08-24 12:17:04
【问题描述】：
我创建了一个非常基本的 Spring boot 项目，我想对 MongoDB (v 4.4.4) 执行一个简单的查询：
@SpringBootTest
class DemoApplicationTests {
@Autowired
MongoOperations operations;
@Test
void sliceSimple() {
final Criteria criteria = Criteria.where("_id").is(new ObjectId("5a3931f6d60180000f16db8c"));
Query query = Query.query(criteria);
query.fields().slice("subcategories", 0, 1);
operations.find(query, Category.class);
}
}
public class Category {
public List<String> subcategories;
}
但结果有异常：
Can't find a codec for class [Ljava.lang.Integer;.
org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for class [Ljava.lang.Integer;.
at org.bson.internal.CodecCache.lambda$getOrThrow$1(CodecCache.java:52)
at java.base/java.util.Optional.orElseThrow(Optional.java:408)
at org.bson.internal.CodecCache.getOrThrow(CodecCache.java:51)
at org.bson.internal.OverridableUuidRepresentationCodecRegistry.get(OverridableUuidRepresentationCodecRegistry.java:72)
at org.bson.internal.ChildCodecRegistry.get(ChildCodecRegistry.java:52)
at org.bson.codecs.DocumentCodec.writeValue(DocumentCodec.java:202)
at org.bson.codecs.DocumentCodec.writeMap(DocumentCodec.java:217)
at org.bson.codecs.DocumentCodec.writeValue(DocumentCodec.java:200)
at org.bson.codecs.DocumentCodec.writeMap(DocumentCodec.java:217)
at org.bson.codecs.DocumentCodec.encode(DocumentCodec.java:159)
at org.bson.codecs.DocumentCodec.encode(DocumentCodec.java:46)
at org.bson.BsonDocumentWrapper.getUnwrapped(BsonDocumentWrapper.java:195)
at org.bson.BsonDocumentWrapper.isEmpty(BsonDocumentWrapper.java:115)
at com.mongodb.internal.operation.DocumentHelper.putIfNotNullOrEmpty(DocumentHelper.java:43)
at com.mongodb.internal.operation.FindOperation.getCommand(FindOperation.java:826)
at com.mongodb.internal.operation.FindOperation.access$1700(FindOperation.java:80)
at com.mongodb.internal.operation.FindOperation$4.create(FindOperation.java:893)
at com.mongodb.internal.operation.CommandOperationHelper.executeCommandWithConnection(CommandOperationHelper.java:221)
at com.mongodb.internal.operation.FindOperation$1.call(FindOperation.java:658)
at com.mongodb.internal.operation.FindOperation$1.call(FindOperation.java:652)
at com.mongodb.internal.operation.OperationHelper.withReadConnectionSource(OperationHelper.java:583)
at com.mongodb.internal.operation.FindOperation.execute(FindOperation.java:652)
at com.mongodb.internal.operation.FindOperation.execute(FindOperation.java:80)
at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.execute(MongoClientDelegate.java:170)
at com.mongodb.client.internal.MongoIterableImpl.execute(MongoIterableImpl.java:135)
at com.mongodb.client.internal.MongoIterableImpl.iterator(MongoIterableImpl.java:92)
at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:2807)
at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:2543)
at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:2525)
at org.springframework.data.mongodb.core.MongoTemplate.find(MongoTemplate.java:847)
at org.springframework.data.mongodb.core.MongoTemplate.find(MongoTemplate.java:833)
at com.example.demo.DemoApplicationTests.sliceSimple(DemoApplicationTests.java:22)
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:566)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688)
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$6(TestMethodTestDescriptor.java:210)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$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$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:108)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:96)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:75)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:99)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:79)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:75)
at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:61)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
at com.sun.proxy.$Proxy2.stop(Unknown Source)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.stop(TestWorker.java:133)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:414)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
at java.base/java.lang.Thread.run(Thread.java:834)
看slice(String, int, int)的定义，有一个Integer[]的用法：
/**
* Project a {@code $slice} of the array {@code field} using the first {@code size} elements starting at
* {@code offset}.
*
* @param field the document field name to project, must be an array field.
* @param offset the offset to start at.
* @param size the number of elements to include.
* @return {@code this} field projection instance.
*/
public Field slice(String field, int offset, int size) {
slices.put(field, new Integer[] { offset, size });
return this;
}
有人知道发生了什么吗？我的配置中是否缺少某些内容？ 我的 build.gradle：
plugins {
id 'org.springframework.boot' version '2.5.4'
id 'io.spring.dependency-management' version '1.0.11.RELEASE'
id 'java'
}
group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '11'
repositories {
mavenCentral()
}
dependencies {
implementation 'org.springframework.boot:spring-boot-starter-data-mongodb'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
}
test {
useJUnitPlatform()
}
附言。我还尝试对整数数组使用自定义转换器：
public class JavaIntegerArrayToListConverter implements Converter<Integer[], List<Integer>> {
@Override
public List<Integer> convert(final Integer[] source) {
return source == null ? null : Arrays.asList(source);
}
}
并注册：
@Primary
@Bean
public MongoTemplate mongoTemplate(MongoDatabaseFactory mongoDbFactory,
MappingMongoConverter mappingMongoConverter) {
mappingMongoConverter.setCustomConversions(new MongoCustomConversions(
Collections.singletonList(new JavaIntegerArrayToListConverter())));
mappingMongoConverter.afterPropertiesSet();
return new MongoTemplate(mongoDbFactory, mappingMongoConverter);
}
但是没有任何效果。
提前感谢您的帮助。
【问题讨论】：
标签： java spring mongodb spring-boot