在 JAX-RS 中使用 @Context、@Provider 和 ContextResolver

I'm just getting acquainted with implementing REST web services in Java using JAX-RS and I ran into the following problem. One of my resource classes requires access to a storage backend, which is abstracted away behind a StorageEngine interface. I would like to inject the current StorageEngine instance into the resource class serving the REST requests and I thought a nice way of doing this would be by using the @Context annotation and an appropriate ContextResolver class. This is what I have so far:

在 MyResource.java 中:

class MyResource {
    @Context StorageEngine storage;
    [...]
}

在StorageEngineProvider.java中:

@Provider
class StorageEngineProvider implements ContextResolver<StorageEngine> {
    private StorageEngine storage = new InMemoryStorageEngine();

    public StorageEngine getContext(Class<?> type) {
        if (type.equals(StorageEngine.class))
            return storage;
        return null;
    }
}

我正在使用 com.sun.jersey.api.core.PackagesResourceConfig 自动发现提供程序和资源类，并根据日志获取 StorageEngineProvider 类很好(时间戳和不必要的东西故意遗漏):

INFO: Root resource classes found:
    class MyResource
INFO: Provider classes found:
    class StorageEngineProvider

@Path("/something/")
class MyResource {
    @Context
    javax.ws.rs.ext.Providers providers;

    @GET
    public Response get() {
        ContextResolver<StorageEngine> resolver = providers.getContextResolver(StorageEngine.class, MediaType.WILDCARD_TYPE);
        StorageEngine engine = resolver.get(StorageEngine.class);
        ...
    }
}