Ocelot 使用 AddDelegatingHandler处理超时异常的例子
时间: 2024-02-02 17:04:44 浏览: 33
以下是一个在Ocelot中使用AddDelegatingHandler处理超时异常的示例:
1. 在Ocelot配置文件中添加以下代码:
```
{
"ReRoutes": [
{
"DownstreamPathTemplate": "/api/{everything}",
"DownstreamScheme": "http",
"DownstreamHostAndPorts": [
{
"Host": "localhost",
"Port": 5001
}
],
"UpstreamPathTemplate": "/api/{everything}",
"UpstreamHttpMethod": [ "Get" ],
"Timeout": 5000, //设置超时时间
"DelegatingHandlers": [ "CustomDelegatingHandler" ]
}
],
"GlobalConfiguration": {
"BaseUrl": "http://localhost:5000",
"DelegatingHandlers": [ "CustomDelegatingHandler" ]
}
}
```
上述代码中,我们在一个ReRoutes配置项中定义了一个超时时间为5秒的路由,并将CustomDelegatingHandler添加到DelegatingHandlers列表中。我们还在GlobalConfiguration中添加了CustomDelegatingHandler,以便在所有路由中使用。
2. 创建一个CustomDelegatingHandler类,代码如下:
```
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using Ocelot.Logging;
public class CustomDelegatingHandler : DelegatingHandler
{
private readonly int _timeout;
private readonly IOcelotLogger _logger;
public CustomDelegatingHandler(int timeout, IOcelotLoggerFactory loggerFactory)
{
_timeout = timeout;
_logger = loggerFactory.CreateLogger<CustomDelegatingHandler>();
}
protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
using (var cts = new CancellationTokenSource())
{
var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, cts.Token);
linkedCts.CancelAfter(_timeout);
try
{
return await base.SendAsync(request, linkedCts.Token);
}
catch (TaskCanceledException) when (!cancellationToken.IsCancellationRequested && !cts.IsCancellationRequested)
{
_logger.LogWarning($"Request timed out after {_timeout} ms: {request.Method} {request.RequestUri}");
return new HttpResponseMessage(System.Net.HttpStatusCode.RequestTimeout);
}
}
}
}
```
上述代码中,我们定义了一个名为CustomDelegatingHandler的DelegatingHandler类,它接收一个超时时间参数timeout和一个IOcelotLoggerFactory对象来记录日志。在SendAsync方法中,我们使用CancellationTokenSource和linkedCts来设置请求的超时时间,并在请求超时时返回一个带有RequestTimeout状态代码的错误响应。我们还使用OcelotLogger记录了超时日志信息。
3. 在Startup.cs文件中通过以下代码注册CustomDelegatingHandler:
```
public void ConfigureServices(IServiceCollection services)
{
services.AddOcelot()
.AddDelegatingHandler<CustomDelegatingHandler>(true);
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseOcelot().Wait();
}
```
上述代码中,我们使用AddDelegatingHandler方法将CustomDelegatingHandler注册到Ocelot中,并设置shouldThrow属性为true,以便在DelegatingHandler中发生异常时,抛出异常。
这样,我们就可以在Ocelot中使用CustomDelegatingHandler处理超时异常了。