我想使用HTTP PUT动词公开ASP.Net Web Api 2动作来上传文件.这与我们的REST模型一致,因为API代表一个远程文件系统(类似于WebDAV,但实际上是简化的),因此客户端选择资源名称(因此PUT是理想的,POST不是一个合理的选择).
Web Api文档描述了how to upload files using multipart/form-data forms,但没有描述如何使用PUT方法.
您将使用什么来测试这样的API(HTML多部分表单不允许PUT动词)？服务器实现是否类似于the web api documentation中描述的多部分实现(使用MultipartStreamProvider),或者应该如下所示：
[HttpPut]
public async Task<HttpResponseMessage> PutFile(string resourcePath)
{
Stream fileContent = await this.Request.Content.ReadAsStreamAsync();
bool isNew = await this._storageManager.UploadFile(resourcePath,fileContent);
if (isNew)
{
return this.Request.CreateResponse(HttpStatusCode.Created);
}
else
{
return this.Request.CreateResponse(HttpStatusCode.OK);
}
}
解决方法
经过几次测试后,我发布的服务器端代码似乎是正确的.这是一个示例,从任何身份验证/授权/错误处理代码中删除：
[HttpPut]
[Route(@"api/storage/{*resourcePath?}")]
public async Task<HttpResponseMessage> PutFile(string resourcePath = "")
{
// Extract data from request
Stream fileContent = await this.Request.Content.ReadAsStreamAsync();
MediaTypeHeaderValue contentTypeHeader = this.Request.Content.Headers.ContentType;
string contentType =
contentTypeHeader != null ? contentTypeHeader.MediaType : "application/octet-stream";
// Save the file to the underlying storage
bool isNew = await this._dal.SaveFile(resourcePath,contentType,fileContent);
// Return appropriate HTTP status code
if (isNew)
{
return this.Request.CreateResponse(HttpStatusCode.Created);
}
else
{
return this.Request.CreateResponse(HttpStatusCode.OK);
}
}
一个简单的控制台应用程序足以测试它(使用Web Api客户端库)：
using (var fileContent = new FileStream(@"C:\temp\testfile.txt",FileMode.Open))
using (var client = new HttpClient())
{
var content = new StreamContent(fileContent);
content.Headers.ContentType = new MediaTypeHeaderValue("text/plain");
client.BaseAddress = new Uri("http://localhost:81");
HttpResponseMessage response =
await client.PutAsync(@"/api/storage/testfile.txt",content);
}
编辑2018-05-09：
如this comment中所述,如果您计划支持带扩展名({filename}.{extension})的文件名而不强制客户端附加尾部斜杠,则需要修改web.config以将IIS绑定到Web api这些文件类型的应用程序,默认情况下IIS将使用静态文件处理程序来处理看起来像文件名的内容(即包含点的最后一个路径段的URL).我的system.webServer部分如下所示：
<system.webServer>
<handlers>
<!-- Clear all handlers,prevents executing code file extensions or returning any file contents. -->
<clear />
<!-- Favicon static handler. -->
<add name="FaviconStaticFile" path="/favicon.ico" verb="GET" modules="StaticFileModule" preCondition="integratedMode" resourceType="File" requireAccess="Read" />
<!-- By default,only map extensionless URLs to ASP.NET -->
<!-- (the "*." handler mapping is a special Syntax that matches extensionless URLs) -->
<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
<!-- API endpoints must handle path segments including a dot -->
<add name="ExtensionIncludedUrlHandler-Integrated-4.0" path="/api/storage/*" verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
</handlers>
<httpProtocol>
<customHeaders>
<remove name="X-Powered-By" />
</customHeaders>
</httpProtocol>
</system.webServer>
请注意,由于各种限制,某些文件名将无法使用.例如,您无法命名路径段.或者..因为RFC要求替换它,Azure托管服务将不允许冒号作为路径段的最后一个字符,并且IIS默认禁止一组字符.
您可能还希望增加IIS / ASP.NET文件上载大小限制：
<!-- Path specific settings -->
<location path="api/storage">
<system.web>
<httpRuntime maxRequestLength="200000000" />
</system.web>
<system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="200000000" />
</requestFiltering>
</security>
</system.webServer>
</location>
