如何使用 java 配置而不是 XML 声明存储库填充器 bean? [英] How to declare a respository populator bean using java config instead of XML?

问题描述

我正在开发一个基于 Spring 的项目，该项目(到目前为止)完全没有 XML，但现在我遇到了 Spring JPA 存储库填充器:

I am working on a Spring based project that is (so-far) completely XML-free, except now I've hit a wall with the Spring JPA repository populator:

<repository:jackson-populator location="classpath:data.json" />

在java @Configuration 类中如何表达上述内容?

How would the above be expressed in a java @Configuration class?

这篇文章建议直接使用 FactoryBean:https://stackoverflow.com/a/13566712/1746274

This post suggests using the FactoryBean directly: https://stackoverflow.com/a/13566712/1746274

我试过了，我得到的最接近的是以下，但它不太正确.

I tried that and the closest I got was the following but it's not quite right.

@Bean(name="repositoryPopulator")
public RepositoryPopulator getRespositoryPopulator() throws Exception {
    final JacksonRepositoryPopulatorFactoryBean factory =  new JacksonRepositoryPopulatorFactoryBean();
    factory.getObject().setResourceLocation("classpath:test-data.json");
    factory.afterPropertiesSet();
    return factory.getObject();
}

上述结果导致 FactoryBeanNotInitializedException 消息 JacksonRepositoryPopulatorFactoryBean 不支持循环引用.

The above results in a FactoryBeanNotInitializedException with the message JacksonRepositoryPopulatorFactoryBean does not support circular references.

有什么想法吗?

推荐答案

其实很简单:

@Configuration
class ApplicationConfig {

  @Bean
  public JacksonRepositoryPopulatorFactoryBean repositoryPopulator() {

    Resource sourceData = new ClassPathResource("test-data.json");

    JacksonRepositoryPopulatorFactoryBean factory = new JacksonRepositoryPopulatorFactoryBean();
    // Set a custom ObjectMapper if Jackson customization is needed
    factory.setObjectMapper(…);
    factory.setResources(new Resource[] { sourceData });
    return factory;
  }
}

通过返回 FactoryBean 本身，Spring 将负责调用所有必要的回调接口(即 setApplicationContext(…)、setBeanClassLoader(…)代码>等).工厂 bean 是一个 ApplicationListener，因此将侦听 ContextRefreshedEvent 并在 ApplicationContext 完全初始化时触发填充.

By returning the FactoryBean itself, Spring will take care of invoking all the necessarry callback interfaces (i.e. setApplicationContext(…), setBeanClassLoader(…) etc.). The factory bean is an ApplicationListener and thus will listen to the ContextRefreshedEvent and trigger population when the ApplicationContext is fully initialized.

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