尝试使用Spring Data JPA创建自定义存储库时找不到类型错误的属性

Question

我有一个Media实体，其中包含用户上载文件的一些基本字段。为了保存上传文件的字节，我想创建一个包含该功能的自定义存储库。按照Spring文档中的步骤，我创建了一个看起来像这样的接口：

public interface MediaBytesRepository
{
    public byte[] getBytes(Media media) throws IOException;
    public void saveBytes(Media media, byte[] bytes) throws IOException;
    public void appendBytes(Media media, byte[] bytes) throws IOException;
    public void deleteBytes(Media media) throws IOException;
    public boolean bytesExist(Media media) throws IOException;
}

然后，我为此接口提供了一个实现 MediaBytesRepositoryImpl

这样，我就创建了以下接口：

public interface MediaRepository extends JpaRepository<Media, Long>, MediaBytesRepository
{
}

现在，当我启动服务器时，得到以下堆栈跟踪：

SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mediaRepository': FactoryBean threw exception on object creation; nested exception is java.lang.IllegalArgumentException: Could not create query metamodel for method public abstract void com.foo.bar.core.media.MediaBytesRepository.saveBytes(com.foo.bar.core.media.Media,byte[]) throws java.io.IOException!
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:149)
.....
Caused by: java.lang.IllegalArgumentException: Could not create query metamodel for method public abstract void com.foo.bar.core.media.MediaBytesRepository.saveBytes(com.foo.bar.core.media.Media,byte[]) throws java.io.IOException!
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:92)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:162)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:68)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:280)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:148)
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.getObject(RepositoryFactoryBeanSupport.java:125)
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.getObject(RepositoryFactoryBeanSupport.java:41)
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:142)
    ... 20 more
 Caused by: java.lang.IllegalArgumentException: No property save found for type class com.foo.bar.core.media.Media
    at org.springframework.data.mapping.PropertyPath.<init>(PropertyPath.java:73)
    at org.springframework.data.mapping.PropertyPath.<init>(PropertyPath.java:92)
    at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:319)
    at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:333)
    at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:301)
    at org.springframework.data.mapping.PropertyPath.from(PropertyPath.java:265)
    at org.springframework.data.mapping.PropertyPath.from(PropertyPath.java:239)
    at org.springframework.data.repository.query.parser.Part.<init>(Part.java:70)
    at org.springframework.data.repository.query.parser.PartTree$OrPart.<init>(PartTree.java:180)
    at org.springframework.data.repository.query.parser.PartTree$Predicate.buildTree(PartTree.java:260)
    at org.springframework.data.repository.query.parser.PartTree$Predicate.<init>(PartTree.java:240)
    at org.springframework.data.repository.query.parser.PartTree.<init>(PartTree.java:68)
    at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.<init>(PartTreeJpaQuery.java:57)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:90)
    ... 27 more

我找到了类似的帖子，但是那里的建议（全部在同一个程序包中，命名约定）是我已经在做的事情。我所有的媒体类和接口都在同一程序包中，并且使用的是“
Impl”后缀。

有人可以说明为什么我会收到此错误以及如何解决该错误吗？谢谢。

Answer 1

你写了：

那里的建议（全部在同一个程序包中，命名约定）是我已经在做的事情。

你不可以。

重命名MediaBytesRepository为MediaRepositoryCustom。

当然，你需要的实现MediaRepositoryCustom与名称MediaRepositoryImpl。