企业级工作流解决方案(四)--微服务消息处理模型之消息传输通道
消息传输通道我这里只定义了3种,即:localInvoker,HttpInvoker,TcpInvoker,根据实际的情况,还可以进行扩展,比如消息队列,不过这都是后话了,先重点描述一下这3种方式。
LocalInvoker
本地调用直接构造请求参数,直接调用服务端的JsonRpcProcessor服务处理执行服务处理过程,这个不多说。
HttpInvoker
即执行http请求处理过程,由于.net framework和.net core的运行机制有所不同,处理方式也有所不同,但最终都落到服务端的JsonRpcProcessor身上进行处理,.net framework是通过增加IHttpAsyncHandler处理类处理调用请求,需要在web.config中增加处理handlers,
<add name="jsonrpc" type="CK.Sprite.JsonRpcFramework.JsonRpcHandler, CK.Sprite.JsonRpcFramework" verb="*" path="/json.rpc"/>
,实现类代码如下:
public class JsonRpcHandler : IHttpAsyncHandler { public IAsyncResult BeginProcessRequest(HttpContext context, AsyncCallback cb, object extraData) { context.Response.ContentType = "application/json"; var async = new JsonRpcStateAsync(cb, context); async.JsonRpc = GetJsonRpcString(context.Request); JsonRpcProcessor.Process(async,context.Request); return async; } private static string GetJsonRpcString(System.Web.HttpRequest request) { string json = string.Empty; if (request.RequestType == "GET") { json = request.Params["jsonrpc"] ?? string.Empty; } else if (request.RequestType == "POST") { if (request.ContentType == "application/x-www-form-urlencoded") { json = request.Params["jsonrpc"] ?? string.Empty; } else { json = new StreamReader(request.InputStream).ReadToEnd(); } } return json; } }
.net core这边的做法是增加RpcHttpRouter类,实现IRouter接口,并在StartUp的Configure方法中,增加处理Router,最终处理还是落到JsonRpcProcessor身上进行处理,代码如下:
public void Configure(IApplicationBuilder app, IHostingEnvironment env) { app.UseAbp(); //Initializes ABP framework. Should be called first. // ...... app.Map("/json.rpc", rpcApp => { rpcApp.UseJsonRpc(); }); } public static IApplicationBuilder UseJsonRpc(this IApplicationBuilder app) { if (app == null) { throw new ArgumentNullException(nameof(app)); } var router = new RpcHttpRouter(); return app.UseRouter(router); } public class RpcHttpRouter : IRouter { public VirtualPathData GetVirtualPath(VirtualPathContext context) { return null; } /// <summary> /// Takes a route/http contexts and attempts to parse, invoke, respond to an Rpc request /// </summary> /// <param name="context">Route context</param> /// <returns>Task for async routing</returns> public async Task RouteAsync(RouteContext context) { try { string jsonString = await GetJsonRpcString(context); string responseJson = await JsonRpcProcessor.Process(jsonString); if (string.IsNullOrEmpty(responseJson)) { //No response required, but status code must be 204 context.HttpContext.Response.StatusCode = 204; context.MarkAsHandled(); return; } context.HttpContext.Response.ContentType = "application/json"; await context.HttpContext.Response.WriteAsync(responseJson); context.MarkAsHandled(); } catch (Exception ex) { context.MarkAsHandled(); } } private async Task<string> GetJsonRpcString(RouteContext context) { string jsonString; if (context.HttpContext.Request.Body == null) { jsonString = null; } else { using (StreamReader streamReader = new StreamReader(context.HttpContext.Request.Body, Encoding.UTF8, detectEncodingFromByteOrderMarks: true, bufferSize: 1024, leaveOpen: true)) { try { jsonString = await streamReader.ReadToEndAsync(); } catch (TaskCanceledException ex) { throw new CPlatformException("Cancelled while reading the request.", ex); } jsonString = jsonString.Trim(); } } return jsonString; } } public static class RouteContextExtensions { public static void MarkAsHandled(this RouteContext context) { context.Handler = c => Task.FromResult(0); } }
TcpInvoker
Tcp方式的调用后续文章会继续进行分解,也是微服务核心价值的地方。
posted on 2019-05-03 17:44 spritekuang 阅读(395) 评论(0) 编辑 收藏 举报