djyweb_ams/web/djy_AfrApi/Milldlewares/CommonDataCacheMiddleware.cs

using Common.Tools;
using Common.Utilities;
using djy_AfrApi.Attributes;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Controllers;
using Newtonsoft.Json;
using System.IO;
using System.Threading.Tasks;

namespace djy_AfrApi.Milldlewares
{
    public class CommonDataCacheMiddleware
    {
        private readonly RequestDelegate next;

        public CommonDataCacheMiddleware(RequestDelegate next)
        {
            this.next = next;
        }
        public async Task InvokeAsync(HttpContext context)
        {
            var endpoint = context.GetEndpoint();

            if (endpoint?.Metadata?.GetMetadata<RedisCachingAttribute>() == null)
            {
                await next(context);
            }
            else
            {
                var actionDescriptor = endpoint.Metadata.GetMetadata<ControllerActionDescriptor>();
                if (actionDescriptor?.ActionName == null)
                {
                    await next(context);
                }
                else
                {
                    string redisKey = actionDescriptor.ActionName + "Cache";
                    string cacheData = YsRedisHelp.RedisGetString(redisKey);
                    if (string.IsNullOrEmpty(cacheData))
                    {
                        // 存储响应数据
                        using (MemoryStream memoryStream = new MemoryStream())
                        {
                            // 使用自定义的响应流，将所有写入重定向到内存流
                            var originalBodyStream = context.Response.Body;
                            context.Response.Body = memoryStream;

                            try
                            {
                                await next(context);

                                // 从内存流读取响应内容
                                memoryStream.Seek(0, SeekOrigin.Begin);
                                string responseBody = new StreamReader(memoryStream).ReadToEnd();

                                Response response = JsonConvert.DeserializeObject<Response>(responseBody);
                                if (response.Code == 200)
                                {
                                    YsRedisHelp.RedisSet<string>(redisKey, responseBody, 60 * 5);
                                }

                                // 将响应内容写回原始响应流
                                memoryStream.Seek(0, SeekOrigin.Begin);
                                await memoryStream.CopyToAsync(originalBodyStream);
                            }
                            finally
                            {
                                // 恢复原始响应流
                                context.Response.Body = originalBodyStream;
                            }
                        }
                    }
                    else
                    {
                        context.Response.ContentType = "application/json";
                        await context.Response.WriteAsync(cacheData).ConfigureAwait(false);
                    }
                }
            }
        }
    }
}