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，我面临着自定义RepositoryEntityLinks类的问题。下面的类给出了构造函数自变量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());
  }
}

我唯一更改的是构造函数参数，从PluginRegistry到Java8PluginRegistry。

当我向此类添加@Component注释时，应用程序无法从此问题开始：

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？在此先感谢:)

Answer 1

RepositoryRestMvcConfiguration不公开类型为Java8PluginRegistry的bean。最近的更新可能会改变这种行为。如果遵循在RepositoryEntityLinks类中创建常规RepositoryRestMvcConfiguration bean的惯例，则可以创建自定义CustomRepositoryEntityLinks类的bean，如以下代码片段所示（创建CustomRepositoryEntityLinks实例的其他参数省略了） ）。

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