org.springframework.data.mapping.model.MappingInstantiationException：无法使用带参数的构造函数 NO_CONSTRUCTOR 实例化 void

Question

我正在使用 spring data mongo 使用 mongo 存储库方法通过 id 更新一个属性

@Repository
public interface CategoryRepository extends MongoRepository<CategoryEntity,Integer> {
  @Query("{'id' : ?0}, {$set: {'count' : ?1}}")
  void updateCountById(Integer id, Integer count);
}

调用此函数时出现以下异常

org.springframework.data.mapping.model.MappingInstantiationException: Failed to instantiate void using constructor NO_CONSTRUCTOR with arguments
    at org.springframework.data.mapping.model.ReflectionEntityInstantiator.createInstance(ReflectionEntityInstantiator.java:65)
    at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator.createInstance(ClassGeneratingEntityInstantiator.java:89)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:344)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:317)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:250)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:246)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:98)
    at org.springframework.data.mongodb.core.MongoTemplate$ProjectingReadCallback.doWith(MongoTemplate.java:3186)
    at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:2788)
    at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:2542)
    at org.springframework.data.mongodb.core.ExecutableFindOperationSupport$ExecutableFindSupport.doFind(ExecutableFindOperationSupport.java:215)
    at org.springframework.data.mongodb.core.ExecutableFindOperationSupport$ExecutableFindSupport.oneValue(ExecutableFindOperationSupport.java:127)
    at org.springframework.data.mongodb.repository.query.AbstractMongoQuery.lambda$getExecution$4(AbstractMongoQuery.java:153)
    at org.springframework.data.mongodb.repository.query.AbstractMongoQuery.doExecute(AbstractMongoQuery.java:126)
    at org.springframework.data.mongodb.repository.query.AbstractMongoQuery.execute(AbstractMongoQuery.java:101)
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:137)
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:121)
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:159)
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:138)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:80)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:215)
    at com.sun.proxy.$Proxy135.updatePriorityById(Unknown Source)   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.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:137)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:215)

Answer 1

您正在使用 MongoDB，

@Query

用于数据检索。要进行更新，请使用

@Update

。正如文档中所解释的。

public interface CategoryRepository extends MongoRepository<CategoryEntity,Integer> {
  @Update("{'id' : ?0}, {$set: {'count' : ?1}}")
  void updateCountById(Integer id, Integer count);
}

提示： 您不需要 Spring Data 存储库的

@Repository

，为您节省一行代码（而且不会太伤您的头；））。