在spring配置文件中设置资源

Question

我正在尝试在 spring 配置中配置推土机。使用 xml 配置时会像

<bean class="org.dozer.spring.DozerBeanMapperFactoryBean">
    <property name="mappingFiles" value="classpath*:dozer/**/*.dzr.xml"/>
</bean>

如何在配置文件中定义资源。我尝试使用ctx.getResource()，但无法访问 Configuration 类中的 ApplicationContext。

我尝试了 ContextRefreshedEvent 并从那里添加资源，但仍然没有运气。 （afterPropertiesSet 已经被调用并且添加的映射不起作用）

public class ContextRefreshedEventBuilder extends ContextRefreshedEvent {
public ContextRefreshedEventBuilder(ApplicationContext ctx) {
    super(ctx);
    DozerBeanMapperFactoryBean mapper = ctx.getBean(DozerBeanMapperFactoryBean.class);
    try {
        mapper.setMappingFiles(ctx.getResources("classpath*:dozer/**/*.dzr.xml"));
    } catch (IOException e) {
        e.printStackTrace();
    }
}
}

也尝试使用 ClassPathResource 但找不到正确的方法

DozerBeanMapperFactoryBean mapper = new DozerBeanMapperFactoryBean();
mapper.setMappingFiles(new Resource[]{new ClassPathResource("classpath*:dozer/**/*.dzr.xml")});
return mapper;

如何添加 ClassPathResource 作为映射位置？

---答案---

@Bean
public DozerBeanMapperFactoryBean configDozer() throws IOException {
    DozerBeanMapperFactoryBean mapper = new DozerBeanMapperFactoryBean();
    Resource[] resources = new PathMatchingResourcePatternResolver().getResources("classpath*:dozer/**/*.dzr.xml");
    mapper.setMappingFiles(resources);
    return mapper;
}

Answer 1

您需要使用ResourcePatternResolver 将classpath*:dozer/**/*.dzr.xml 转换为Resource[]。您可以使用 2 个主要选项。

1. 将ApplicationContext 注入您的配置类，将其转换为ResourcePatternResolver 并使用getResources 方法。 Al Spring 默认应用程序上下文实现实现了ResourcePatternResolver 接口。
2. 创建一个PathMatchingResourcePatternResolver，无论是否包含前面提到的上下文。
3. 将ResourcePatternUtils 与注入的ResourceLoader 一起使用。

使用 ResourcePatternUtils

@Configuration
public class MyConfiguration {

    @Autowired
    private ResourceLoader resourceLoader;

    public DozerBeanMapperFactoryBean mapper() throws IOException {
        DozerBeanMapperFactoryBean mapper = new DozerBeanMapperFactoryBean();
        // ResourceLoader is allowed to be null when using the ResourceLoaderUtils.
        ResourcePatternResolver resolver = ResourceLoaderUtils.getResourcePatternResolver(resourceLoader);
        Resource[] mappingFiles = resolver.getResources("classpath*:dozer/**/*.dzr.xml");
        mapper.setMappingFiles(mappingFiles);
        return mapper;
    }
}

最后一种方法的优点是您不受PathMatchingResourcePatternResolver 的约束，而只是界面。实用程序类根据注入的ResourceLoader 确定它的作用。人们应该更喜欢这种加载资源的方式。

使用 ApplicationContext

@Configuration
public class MyConfiguration {

    @Autowired
    private ApplicationContext context;

    public DozerBeanMapperFactoryBean mapper() throws IOException {
        DozerBeanMapperFactoryBean mapper = new DozerBeanMapperFactoryBean();
        Resource[] mappingFiles = ((ResourcePatternResolver) context).getResources("classpath*:dozer/**/*.dzr.xml");
        mapper.setMappingFiles(mappingFiles);
        return mapper;
    }
}

使用 PathMatchingResourcePatternResolver

@Configuration
public class MyConfiguration {

    private PathMatchingPatternResolver resolver = new PathMatchingPatternResolver();

    public DozerBeanMapperFactoryBean mapper() throws IOException {
        DozerBeanMapperFactoryBean mapper = new DozerBeanMapperFactoryBean();
        Resource[] mappingFiles = resolver.getResources("classpath*:dozer/**/*.dzr.xml");
        mapper.setMappingFiles(mappingFiles);
        return mapper;
    }
}

或者如果你想重用已经存在的ResourceLoader 一个稍微不同的版本：

@Configuration
public class MyConfiguration {

    @Autowired
    private ResourceLoader resourceLoader;

    public DozerBeanMapperFactoryBean mapper() throws IOException {
        DozerBeanMapperFactoryBean mapper = new DozerBeanMapperFactoryBean();
        Resource[] mappingFiles = new PathMatchingPatternResolver(resourceLoader).getResources("classpath*:dozer/**/*.dzr.xml");
        mapper.setMappingFiles(mappingFiles);
        return mapper;
    }
}