netcore api请求日志输出中间件

 
    /// <summary>
    /// 统一错误处理中间件
    /// </summary>
    public class CustomExceptionMiddleware
    {
        private readonly RequestDelegate _next;
        public CustomExceptionMiddleware(RequestDelegate next)
        {
            _next = next;
        }
        public async Task InvokeAsync(HttpContext context)
        {
            var responseBodyStream = context.Response.Body;
            try
            {
                await LogRequest(context.Request);
                //Copy a pointer to the original response body stream
                using (var ms = new MemoryStream())
                {
                    context.Response.Body = ms;
                    await _next(context);
                    await LogResponse(context.Response, ms);
                    ms.Position = 0;
                    await ms.CopyToAsync(responseBodyStream);
                }
            }
            catch (Exception ex)
            {
                LogHelper.Error("Error", ex);
                await HandleExceptionAsync(context, responseBodyStream, ex).ConfigureAwait(true);
            }
        }
        private async Task HandleExceptionAsync(HttpContext context, Stream body, Exception exception)
        {
            context.Response.ContentType = "application/json";
            context.Response.StatusCode = 200;// (int)HttpStatusCode.InternalServerError;
            var data = new { code = 500, message = exception.Message };
            var result = JsonHelper.ToJson(data);
            using (var ms = new MemoryStream())
            {
                //ms.Seek(0, SeekOrigin.Begin);
                await ms.WriteAsync(Encoding.UTF8.GetBytes(result));
                ms.Seek(0, SeekOrigin.Begin);
                await ms.CopyToAsync(body);
            }
        }
        #region 日志
        private async Task<string> FormatRequest(HttpRequest request)
        {
            var body = "";
            if (request.ContentLength > 0)
            {
                if (!request.Body.CanSeek)
                {
                    request.EnableBuffering();
                    await request.Body.DrainAsync(CancellationToken.None);
                    request.Body.Seek(0L, SeekOrigin.Begin);
                }
                var contentType = request.ContentType;
                var mediaType = contentType == null ? default(MediaType) : new MediaType(contentType);
                var encoding = mediaType.Encoding;
                if (encoding == null)
                {
                    encoding = Encoding.UTF8;
                }
                using (StreamReader sr = new StreamReader(request.Body, encoding, true, 1024, true))//这里注意Body部分不能随StreamReader一起释放
                {
                    body = await sr.ReadToEndAsync();
                    request.Body.Seek(0, SeekOrigin.Begin);//内容读取完成后需要将当前位置初始化，否则后面的InputFormatter会无法读取
                }
            }
            return body;
        }
        private async Task LogResponse(HttpResponse response, MemoryStream ms)
        {
            ms.Position = 0;
            var body = await new StreamReader(ms).ReadToEndAsync();
            response.Body.Seek(0, SeekOrigin.Begin);//内容读取完成后需要将当前位置初始化，否则后面的InputFormatter会无法读取
            LogHelper.Info($"id:{Thread.GetCurrentProcessorId()};Code:{response.StatusCode};body:{body}");
        }
        /// <summary>
        /// 请求日志
        /// </summary>
        /// <param name="request"></param>
        /// <returns></returns>
        private async Task LogRequest(HttpRequest request)
        {
            var method = request.Method;
            var query = "";
            if (request.Query.Count > 0)
            {
                query = request.QueryString.Value;
            }
            var form = new StringBuilder();
            if (method.Equals("post", StringComparison.OrdinalIgnoreCase) && request.HasFormContentType)
            {
                foreach (var item in request.Form)
                {
                    form.Append($"{item.Key}={item.Value}&");
                }
            }
            var body = await FormatRequest(request);
            LogHelper.Info($"id:{Thread.GetCurrentProcessorId()};api:{request.Host}{request.Path};method:{method};query:{query}; form:{form.ToString()}; body:{body}");
        }
        #endregion
    }