java - 没有可用的 'org.springframework.data.rest.core.util.Java8PluginRegistry' 类型的合格 bean

Question

作为将 spring 应用程序迁移到 springboot (2.1.7) 的一部分，我遇到了自定义 RepositoryEntityLinks 类的问题。下面的类给出了构造函数参数 PluginRegistry 的编译问题，因此我将其更改为 Java8PluginRegistry :

之前:

public class CustomRepositoryEntityLinks extends RepositoryEntityLinks {

  private final ResourceMappings mappings;
  private final RepositoryRestConfiguration config;

  public CustomRepositoryEntityLinks(
          Repositories repositories,
          ResourceMappings mappings,
          RepositoryRestConfiguration config,
          PagingAndSortingTemplateVariables templateVariables,
          PluginRegistry<BackendIdConverter, Class<?>> idConverters) {

    super(repositories, mappings, config, templateVariables, idConverters);

    this.mappings = mappings;
    this.config = config;

  }

  @Override
  public LinkBuilder linkFor(Class<?> type) {
    ResourceMetadata metadata = mappings.getMetadataFor(type);
    return new CustomRepositoryLinkBuilder(metadata, config.getBaseUri());
  }
}

之后:

public class CustomRepositoryEntityLinks extends RepositoryEntityLinks {

  private final ResourceMappings mappings;
  private final RepositoryRestConfiguration config;

  public CustomRepositoryEntityLinks(
          Repositories repositories,
          ResourceMappings mappings,
          RepositoryRestConfiguration config,
          PagingAndSortingTemplateVariables templateVariables,
          Java8PluginRegistry<BackendIdConverter, Class<?>> idConverters) {

    super(repositories, mappings, config, templateVariables, idConverters);

    this.mappings = mappings;
    this.config = config;

  }

  @Override
  public LinkBuilder linkFor(Class<?> type) {
    ResourceMetadata metadata = mappings.getMetadataFor(type);
    return new CustomRepositoryLinkBuilder(metadata, config.getBaseUri());
  }
}

我唯一改变的是构造函数参数，从 PluginRegistry 更改为 Java8PluginRegistry。

当我向此类添加 @Component 注释时，应用程序无法启动并出现此问题:

2019-12-20 18:16:33,491|11782|main|WARN|org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext|Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'customRepositoryEntityLinks' defined in file [C:\com\custom\web\common\CustomRepositoryEntityLinks.class]: Unsatisfied dependency expressed through constructor parameter 4; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.springframework.data.rest.core.util.Java8PluginRegistry<org.springframework.data.rest.webmvc.spi.BackendIdConverter, java.lang.Class<?>>' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}

***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 4 of constructor in com.web.common.CustomRepositoryEntityLinks required a bean of type 'org.springframework.data.rest.core.util.Java8PluginRegistry' that could not be found.


Action:

Consider defining a bean of type 'org.springframework.data.rest.core.util.Java8PluginRegistry' in your configuration.

有人可以帮忙吗？预先感谢:)

Answer 1

RepositoryRestMvcConfiguration 不公开 Java8PluginRegistry 类型的 bean。这种行为可能会随着最近的更新而改变。如果您遵循在 RepositoryRestMvcConfiguration 类中创建常规 RepositoryEntityLinks bean 的约定，则可以创建自定义 CustomRepositoryEntityLinks 类的 bean，如下所示如以下代码片段所示(创建 CustomRepositoryEntityLinks 实例的其他参数省略)。

    @Bean
    public CustomRepositoryEntityLinks entityLinks(PluginRegistry<BackendIdConverter, Class<?>> backendIdConverterRegistry, ...) {
        return new CustomRepositoryEntityLinks(..., ..., ..., ..., Java8PluginRegistry.of(backendIdConverterRegistry));
    }