对于一些返回数据非常简单的 Web API,比如我们今天遇到的“返回指定用户的未读站内短消息数”,返回数据就是一个数字,如果通过 http response body 返回数据,显得有些奢侈。何不直接通过 http headers 返回呢?节能又环保。于是今天在 ASP.NET Web API 中实际试了一下,证明是可行的。
在 Web API 服务端借助 HttpResponseMessage ,可以很轻松地实现,代码如下:
public class MessagesController : ApiController { [Route("api/messages/user-{userId}/unread/count")] public async Task<HttpResponseMessage> GetUserUnreadMessageCount(int userId) { var unreadCount = 10; var response = Request.CreateResponse(HttpStatusCode.OK); response.Headers.Add("X-RESULT-COUNT", unreadCount.ToString()); return response; } }
而调用客户端只需直接从 http headers 中读取数据,无需从 http response body 中读取(如果用 HttpClient 就省掉了 Content.ReadAsStringAsync 操作),从而节省了资源。代码如下:
public class WebApiTest { [Fact] public async Task Get_User_Unread_Message_Count() { using (var client = new HttpClient()) { client.BaseAddress = new System.Uri("www.cnblogs.com"); var userId = 1; var response = await client.GetAsync($"/api/messages/user-{userId}/unread/count"); if (response.IsSuccessStatusCode) { var unreadCount = response.Headers.GetValues("X-RESULT-COUNT").FirstOrDefault(); Console.WriteLine(unreadCount); Assert.Equal(10, int.Parse(unreadCount)); } else { Console.WriteLine(response.StatusCode); Console.WriteLine(await response.Content.ReadAsStringAsync()); } } } }
【参考资料】
Getting a count of returns seen by a RESTful request
Paging in ASP.NET Web API: Using HTTP Headers
时间: 2024-10-14 00:00:41