C# と VB.NET の質問掲示板

■No87874 (abc さん) に返信

> もし何かヒントがありましたらコメント頂ければ幸いです。

紹介した記事のように HttpContext.Items を使うという話はどうなったのですか？

IIS のクラシックモードを使うのは諦めて統合パイプラインモードでやることにしたのですか？

そのあたりをクリアにしてもらえないと、この先私がお役に立てるかどうか分からないのですが・・・

とりあえず、検証に使った HTTP モジュールのコードをアップしておきます。環境は Windows 10
Pro 64-bit, ローカル IIS10, Visual Studio 2015 Cimmunity, .NET 4.6.1 です。

HTTP モジュールが動かないとか文字化けするという問題はありません。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;

public class ResponseContentLogHttpModule : IHttpModule
{
    public ResponseContentLogHttpModule()
    {
    }

    public String ModuleName
    {
        get { return "ResponseContentLogHttpModule"; }
    }

    // In the Init function, register for HttpApplication 
    // events by adding your handlers.
    public void Init(HttpApplication application)
    {
        application.BeginRequest += new EventHandler(this.Application_BeginRequest);
        application.EndRequest += new EventHandler(this.Application_EndRequest);
    }

    private void Application_BeginRequest(Object source, EventArgs e)
    {
        // Create HttpApplication and HttpContext objects to access
        // request and response properties.
        HttpApplication application = (HttpApplication)source;
        HttpContext context = application.Context;
        string filePath = context.Request.FilePath;
        string fileExtension = VirtualPathUtility.GetExtension(filePath);
        if (fileExtension.Equals(".aspx"))
        {
            HttpResponse response = context.Response;
            var filter = new OutputFilterStream(response.Filter);
            response.Filter = filter;
            context.Items["OutputFilterStream"] = filter;
        }
    }

    private void Application_EndRequest(Object source, EventArgs e)
    {
        HttpApplication application = (HttpApplication)source;
        HttpContext context = application.Context;
        string filePath = context.Request.FilePath;
        string fileExtension = VirtualPathUtility.GetExtension(filePath);
        if (fileExtension.Equals(".aspx"))
        {
            var filter = (OutputFilterStream)context.Items["OutputFilterStream"];
            string responseContent = filter.ReadStream();
            WriteLog(responseContent);
        }
    }

    private void WriteLog(string log)
    {
        string responseLogPath = HttpContext.Current.Server.MapPath("~/App_Data/log.txt");
        using (var sw = new StreamWriter(responseLogPath, true))
        {
            sw.WriteLine(log);
        }
    }

    public void Dispose() { }
}

public class OutputFilterStream : Stream
{
    private readonly Stream InnerStream;
    private readonly MemoryStream CopyStream;

    public OutputFilterStream(Stream inner)
    {
        this.InnerStream = inner;
        this.CopyStream = new MemoryStream();
    }

    public string ReadStream()
    {
        lock (this.InnerStream)
        {
            if (this.CopyStream.Length <= 0L ||
                !this.CopyStream.CanRead ||
                !this.CopyStream.CanSeek)
            {
                return String.Empty;
            }

            long pos = this.CopyStream.Position;
            this.CopyStream.Position = 0L;
            try
            {
                return new StreamReader(this.CopyStream).ReadToEnd();
            }
            finally
            {
                try
                {
                    this.CopyStream.Position = pos;
                }
                catch { }
            }
        }
    }


    public override bool CanRead
    {
        get { return this.InnerStream.CanRead; }
    }

    public override bool CanSeek
    {
        get { return this.InnerStream.CanSeek; }
    }

    public override bool CanWrite
    {
        get { return this.InnerStream.CanWrite; }
    }

    public override void Flush()
    {
        this.InnerStream.Flush();
    }

    public override long Length
    {
        get { return this.InnerStream.Length; }
    }

    public override long Position
    {
        get { return this.InnerStream.Position; }
        set { this.CopyStream.Position = this.InnerStream.Position = value; }
    }

    public override int Read(byte[] buffer, int offset, int count)
    {
        return this.InnerStream.Read(buffer, offset, count);
    }

    public override long Seek(long offset, SeekOrigin origin)
    {
        this.CopyStream.Seek(offset, origin);
        return this.InnerStream.Seek(offset, origin);
    }

    public override void SetLength(long value)
    {
        this.CopyStream.SetLength(value);
        this.InnerStream.SetLength(value);
    }

    public override void Write(byte[] buffer, int offset, int count)
    {
        this.CopyStream.Write(buffer, offset, count);
        this.InnerStream.Write(buffer, offset, count);
    }
}