我正在尝试添加一个vary：Accept-Encoding头到对我压缩的文件的响应,as advised earlier.
但是,由于某些原因,这是不可能的 – 无论是从Visual Studio测试服务器还是IIS服务器.
if (url.Contains(".js") || url.Contains(".aspx") || url.Contains(".css"))
{
app.Response.AppendHeader("vary","Accept-Encoding");
app.Response.AppendHeader("varye","Accept-Encoding"); // for testing
app.Response.AppendHeader("varye","Accept-Things"); // for testing
app.Response.AppendHeader("vary","Accept-Stuff"); // for testing
app.Response.AppendHeader("Var","Accept-Items"); // for testing
encodings = encodings.ToLower();
if (encodings.Contains("gzip") || encodings == "*")
{
app.Response.Filter = new GZipStream(baseStream,CompressionMode.Compress);
app.Response.AppendHeader("content-encoding","gzip");
}
}
这导致以下响应标题：
Status=OK - 200 Server=ASP.NET Development Server/10.0.0.0 Date=Fri,21 Oct 2011 12:24:11 GMT X-AspNet-Version=4.0.30319 varye=Accept-Encoding,Accept-Things Var=Accept-Items content-encoding=gzip Cache-Control=public Etag="1CC8F2E9D772300" Content-Type=text/css Content-Length=16200 Connection=Close
您可以看到,vary标题不存在.存在具有相似语法的无意义的头文件,因此在发送之前必须有某些东西取出vary标题.
我不知道它是否相关,但这里是我在web.config中定义我的压缩模块的地方：
<httpModules>
<add name="CompressionModule" type="Utility.HttpCompressionModule"/>
</httpModules>
(其中Utility.HttpCompressionModule是我上面提供的代码摘录所属的类.)
if (url.Contains(".js") || url.Contains(".aspx") || url.Contains(".css"))
{
app.Response.Cache.SetvaryByCustom("Accept-Encoding");
encodings = encodings.ToLower();
if (encodings.Contains("gzip") || encodings == "*")
{
app.Response.Filter = new GZipStream(baseStream,"gzip");
}
但是,标题看起来像这样：
Status=OK - 200 Server=ASP.NET Development Server/10.0.0.0 Date=Mon,24 Oct 2011 09:26:37 GMT content-encoding=gzip Cache-Control=public Etag="1CC7A09FDE77300" vary=* Content-Type=application/x-javascript Content-Length=44447 Connection=Close
(不知道为什么这是应用程序/ x-javascript作为其在HTML中设置为text / javascript,但这是无关紧要的.)
正如你所看到的,我现在有一个不同的标题,但是它被设置为vary = *而不是vary = Accept-Encoding,正如您从压缩模块中的代码所期望的那样.
第二编辑：
我要粘贴整个类的源代码.没有比我已经发布的更多,但它可能有助于掌握正在做什么：
public class HttpCompressionModule : IHttpModule
{
/// <summary>
/// Initializes a new instance of the <see cref="AjaxHttpCompressionModule"/> class.
/// </summary>
public HttpCompressionModule()
{
}
#region IHttpModule Members
/// <summary>
/// disposes of the resources (other than memory) used by the module that implements <see cref="T:System.Web.IHttpModule"/>.
/// </summary>
void IHttpModule.dispose()
{
}
/// <summary>
/// Initializes a module and prepares it to handle requests.
/// </summary>
/// <param name="context">An <see cref="T:System.Web.HttpApplication"/> that provides access to the methods,properties,and events common to all application objects within an ASP.NET application</param>
void IHttpModule.Init(HttpApplication context)
{
context.BeginRequest += (new EventHandler(this.context_BeginRequest));
}
#endregion
/// <summary>
/// Handles the BeginRequest event of the context control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param>
void context_BeginRequest(object sender,EventArgs e)
{
HttpApplication app = (HttpApplication)sender;
string encodings = app.Request.Headers.Get("Accept-Encoding");
Stream baseStream = app.Response.Filter;
if (string.IsNullOrEmpty(encodings))
return;
string url = app.Request.RawUrl.ToLower();
if (url.Contains(".js") || url.Contains(".css") || url.Contains("ajax.ashx"))
{
app.Response.Cache.SetvaryByCustom("Accept-Encoding");
encodings = encodings.ToLower();
if (encodings.Contains("gzip") || encodings == "*")
{
app.Response.Filter = new GZipStream(baseStream,CompressionMode.Compress);
app.Response.AppendHeader("content-encoding","gzip");
}
else if (encodings.Contains("deflate"))
{
app.Response.Filter = new DeflateStream(baseStream,"deflate");
}
}
}
}
此外,这是我的web.config文件的System.Web部分：
<system.web> <!--<compilation debug="true"></compilation>--> <trace enabled="true" traceMode="SortByTime"/> <httpRuntime executionTimeout="180"/> <globalization culture="en-GB" uiCulture="en-GB"/> <!-- custom errors--> <customErrors mode="Off"> </customErrors> <!-- Membership --> <membership defaultProvider="sqlProvider" userIsOnlineTimeWindow="15"> <providers> <clear/> <add name="sqlProvider" type="System.Web.Security.sqlMembershipProvider" connectionStringName="sqlServerAuth" applicationName="mycompany" minrequiredPasswordLength="4" minrequiredNonalphanumericCharacters="0" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="true" passwordFormat="Hashed" maxInvalidPasswordAttempts="1024"/> </providers> </membership> <!-- Roles --> <roleManager enabled="true" cacheRolesInCookie="true" defaultProvider="sqlProvider"> <providers> <clear/> <add connectionStringName="sqlServerAuth" applicationName="mycompany" name="sqlProvider" type="System.Web.Security.sqlRoleProvider"/> </providers> </roleManager> <!-- Authentication --> <anonymousidentification enabled="false"/> <authentication mode="Forms"> <forms name=".AUTH" protection="All" timeout="2" path="/"> </forms> </authentication> <httpModules> <add name="CompressionModule" type="Utility.HttpCompressionModule"/> </httpModules> </system.web>
没有什么可说的.我所了解的这个网站没有其他非标准的东西.有任何想法吗？
解决方法
如其他人所说,这是一个
known issue,IIS压缩模块专门覆盖vary头,并已在
hotfix处理.
如果您无法确保该修补程序已安装,另一个解决方法是使用IIS URL Rewrite在Web.config中附加标题：
<configuration> <system.webServer> <rewrite> <outboundRules> <rule name="Append 'vary: X-Requested-With' header" patternSyntax="ECMAScript"> <match serverVariable="RESPONSE_vary" pattern=".+" /> <action type="Rewrite" value="{R:0},X-Requested-With" replace="true" /> </rule> <rule name="Set 'vary: X-Requested-With' header if no others" patternSyntax="ECMAScript"> <match serverVariable="RESPONSE_vary" pattern=".+" negate="true" /> <action type="Rewrite" value="X-Requested-With" /> </rule> </outboundRules> </rewrite> </system.webServer> </configuration>
