asp.net core web api项目添加自定义中间件的实现

 public class BaseRequest
 {
     public string TimeSpan { get; set; }
 }

public static void Main(string[] args)
 {
     var builder = WebApplication.CreateBuilder(args);
     builder.Services.AddControllers();

     var app = builder.Build();
   
     //这里是自定义添加的中间件
     app.UseRequestCheckMiddleware();
     app.UseAuthorization();
     app.MapControllers();
     app.Run();
 }

public static class ApplicationBuilderExtension
{
     public static IApplicationBuilder UseRequestCheckMiddleware(this IApplicationBuilder builder)
     {
        return builder.UseMiddleware<RequestCheckMiddleware>();
     }
 }

 public class RequestCheckMiddleware
{
    private readonly RequestDelegate _next;
    public RequestCheckMiddleware(RequestDelegate next)
    {
        _next= next;
    }
    public async Task InvokeAsync(HttpContext context)
    {
        HttpRequest request = context.Request;
        //缓存下来允许多次读取
        request.EnableBuffering();
        var reader = new StreamReader(request.Body, Encoding.UTF8);
        string data = await reader.ReadToEndAsync();
        // 重置流的位置以便后续中间件可以读取  
        request.Body.Position = 0;
        try
        {
            var inputJson = JsonSerializer.Deserialize<BaseRequest>(data);
            // 假设 BaseRequest.TimeSpan 是一个 long 类型的 UNIX 时间戳  
            if (string.IsNullOrEmpty(inputJson.TimeSpan))
            {
                await HandleError(context, 500, "时间戳为空！");
                return;
            }

            var requestTime = UnixTimeStampToDateTime(Convert.ToInt64(inputJson.TimeSpan));
            if (DateTime.Now - requestTime > TimeSpan.FromMinutes(2))
            {
                await HandleError(context, 429, "超时请求！");
                return;
            }
            await _next(context);
        }
        catch (Exception ex)
        {
            await HandleError(context, 400, $"处理请求失败: {ex.Message}");
        }
    }
    private async Task HandleError(HttpContext context, int statusCode, string message)
    {
        context.Response.StatusCode = statusCode;
        var result = new { code = statusCode, message = message, result = new object() };
        await context.Response.WriteAsync(JsonSerializer.Serialize(result));
    }

    private DateTime UnixTimeStampToDateTime(long unixTimeStamp)
    {
        // UNIX 时间戳转换为 DateTime  
        DateTime dateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
        dateTime = dateTime.AddSeconds(unixTimeStamp).ToLocalTime();
        return dateTime;
    }
}

 //这里是自定义添加的中间件
  app.UseRequestCheckMiddleware();