webapi 利用 ActionFilter 为 ASP.NET Web API 添加 GZip 压缩功能

淩亂°似流年 2022-05-24 09:10 30阅读 0赞

**webapi 利用 ActionFilter 为 ASP.NET Web API 添加 GZip 压缩功能**

先直接上代码

/// <summary>
        /// 对结果进行压缩处理
        /// </summary>
        public class DeflateCompressionAttribute : ActionFilterAttribute
        {
    
            public override void OnActionExecuted(HttpActionExecutedContext actContext)
            {
                var contentType = actContext.Response.Content.Headers.ContentType.ToString();
                var content = actContext.Response.Content;
                var bytes = content == null ? null : content.ReadAsByteArrayAsync().Result;
                //var zlibbedContent = bytes;
    
                var zipTypeId = GZipSupportedTypeId(actContext);
                if (zipTypeId > 0)
                {
                    if (zipTypeId == 1)
                    {
                        var zlibbedContent = CompressionHelper.GzipDeflateByte(bytes);
                        actContext.Response.Content = new ByteArrayContent(zlibbedContent);
                        actContext.Response.Content.Headers.Remove("Content-Type");
                        actContext.Response.Content.Headers.Add("Content-Encoding", "gzip");
                        actContext.Response.Content.Headers.Add("Content-Type", contentType);
                    }
                    deflate压缩有问题
                    //if (zipTypeId == 2)
                    //{
                    //    zlibbedContent = CompressionHelper.DeflateByte(bytes);
                    //    actContext.Response.Content.Headers.Add("Content-Encoding", "deflate");
                    //}
                }
    
    
                base.OnActionExecuted(actContext);
            }
    
            /// <summary>
            /// Determines if GZip is supported; 0=no support,1=gzip,2=deflate
            /// </summary>
            /// <returns></returns>
            public static int GZipSupportedTypeId(HttpActionExecutedContext actContext)
            {
                var typeId = 0;
                string acceptEncoding = actContext.Request.Headers.AcceptEncoding.ToString();
                if (!string.IsNullOrEmpty(acceptEncoding) &&
                    (acceptEncoding.Contains("gzip") || acceptEncoding.Contains("deflate")))
                {
                    if (acceptEncoding.Contains("deflate"))
                    {
                        typeId = 2;
                    }
                    if (acceptEncoding.Contains("gzip"))
                    {
                        typeId = 1;
                    }
                }
                return typeId;
            }
    
            public class CompressionHelper
            {
                public static byte[] DeflateByte(byte[] str)
                {
                    if (str == null)
                    {
                        return null;
                    }
    
                    using (var output = new MemoryStream())
                    {
                        using (var compressor = new DeflateStream(output, System.IO.Compression.CompressionMode.Compress))
                        {
                            compressor.Write(str, 0, str.Length);
                        }
    
                        return output.ToArray();
                    }
                }
    
    
                public static byte[] GzipDeflateByte(byte[] str)
                {
                    if (str == null)
                    {
                        return null;
                    }
    
                    using (var output = new MemoryStream())
                    {
                        if (true)
                        {
                            using (var gzip = new GZipStream(output, CompressionMode.Compress))
                            {
                                gzip.Write(str, 0, str.Length);
                            }
                        }
                        return output.ToArray();
                    }
                }
            }
        }

public class V1Controller : ApiController  
\{  
    \[DeflateCompression\]  
    public HttpResponseMessage GetCustomers()  
    \{  
  
    \}  
  
或在全局处理的地方统一加也行  
  
config.filters.Add(new DeflateCompressionAttribute());  
config 为 HttpConfiguration   
备注  
  
增加对 Request 中 Accept-Encoding 设定的判断，如果客户端请求包含压缩请求才进行压缩

被注释的部分是利用了第三方库来进行，可以视情况来自定义替换为其他库

\--- end ---