https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#resources

https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#context-functionality-resources

an app-context is also a ResourceLoader


https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#resources-resource

public interface InputStreamSource {
    InputStream getInputStream() throws IOException;
}
public interface Resource extends InputStreamSource {
    boolean exists();
    boolean isOpen();
    URL getURL() throws IOException;
    File getFile() throws IOException;
    Resource createRelative(String relativePath) throws IOException;
    String getFilename();
    String getDescription();
}

impls:
* UrlResource (http:, file:, ftp:, classpath:)
* ClassPathResource
* FileSystemResource
* ServletContextResource
* InputStreamResource
* ByteArrayResource

public interface ResourceLoader {
    Resource getResource(String location);
}

Resource abc = ctx.getResource("...")

public interface ResourceLoaderAware {
    void setResourceLoader(ResourceLoader resourceLoader);
}

We can also autowire ResourceLoader if needed:

@Autowired ResourceLoader rL;