Exception을 mail로 보내야지 될 때가 많아서, Exception handler를 간단하게 제작
가장 Key Point는 HttpContext static Member를 이용해서, web에서 발생된 Error도 같이 표현하고 있다는 것이 가장 좋은 점 같다.
/// <summary>HtmlError Object.</summary>
public class ExceptionToHtmlConverter
{
public enum ErrorInfoType
{
Exception,
Context
};
private delegate string ErrorRendererDelegate(string headerString, NameValueCollection collection);
static private Hashtable GetErrorInfo(Exception exception)
{
Hashtable errorTable = new Hashtable();
if(exception == null)
{
throw new ArgumentNullException("exception");
}
// Populate Error Information Collection
ArrayList errorInfoArray = new ArrayList();
while(exception != null)
{
// Populate Error Information Collection
NameValueCollection errorInfo = new NameValueCollection();
errorInfo.Add("Exception Type", exception.GetType().ToString());
errorInfo.Add("Message", exception.Message);
errorInfo.Add("Source", exception.Source);
errorInfo.Add("TargetSite", exception.TargetSite.ToString());
errorInfo.Add("StackTrace", exception.StackTrace);
errorInfoArray.Add(errorInfo);
exception = exception.InnerException;
}
errorTable.Add(ErrorInfoType.Exception, errorInfoArray.ToArray());
if(HttpContext.Current != null)
{
Hashtable info = new Hashtable();
info.Add("QueryString", HttpContext.Current.Request.QueryString);
info.Add("Form", HttpContext.Current.Request.Form);
info.Add("Cookies", HttpContext.Current.Request.Cookies);
info.Add("Session", HttpContext.Current.Session);
info.Add("Server Variables", HttpContext.Current.Request.ServerVariables);
errorTable.Add(ErrorInfoType.Context, info);
}
return errorTable;
}
/// <summary>Returns HTML an formatted error message.</summary>
static public string GetHtmlError(Exception Ex)
{
if(Ex == null)
{
throw new ArgumentNullException("Ex");
}
// Error Message Header
StringBuilder sb = new StringBuilder();
Hashtable errorTable = GetErrorInfo(Ex);
ErrorRendererDelegate renderer = CollectionToHtmlTable;
if(HttpContext.Current != null)
{
sb.AppendFormat("<font face=\"Arial\" size=\"4\" color=\"red\">An error occurred at {0}<br><font size=\"3\"> {1}</font></font><br><br>", HttpContext.Current.Request.Url.ToString(), Ex.Message);
}
// Populate Error Information Collection
foreach(NameValueCollection errorInfo in errorTable[ErrorInfoType.Exception] as object[])
{
// Error Information
sb.Append(renderer("Error Information", BuildCollection(errorInfo)));
}
if(errorTable[ErrorInfoType.Context] != null)
{
Hashtable info = errorTable[ErrorInfoType.Context] as Hashtable;
foreach(DictionaryEntry entry in info)
{
sb.AppendFormat("<BR><BR>\n{0}", renderer(entry.Key as string, BuildCollection(entry.Value as ICollection)));
}
}
return sb.ToString();
}
/// <summary>Returns HTML an formatted error message.</summary>
static public string GetTextError(Exception Ex)
{
if(Ex == null)
{
throw new ArgumentNullException("Ex");
}
// Error Message Header
StringBuilder sb = new StringBuilder();
Hashtable errorTable = GetErrorInfo(Ex);
ErrorRendererDelegate renderer = CollectionToTextTable;
// Populate Error Information Collection
foreach(NameValueCollection errorInfo in errorTable[ErrorInfoType.Exception] as object[])
{
// Error Information
sb.Append(renderer("Error Information", BuildCollection(errorInfo)));
}
if(errorTable[ErrorInfoType.Context] != null)
{
Hashtable info = errorTable[ErrorInfoType.Context] as Hashtable;
foreach(DictionaryEntry entry in info)
{
sb.AppendFormat("\r\n{0}", renderer(entry.Key as string, BuildCollection(entry.Value as ICollection)));
}
}
return sb.ToString();
}
#region Private Methods
static private string CollectionToHtmlTable(string headerString, NameValueCollection collection)
{
// Heading Template
const string heading = @"
<tr>
<td bgcolor=""#666666"" colspan=""2"">
<font face=""Arial"" color=""white""><b> {0}</b></font>
</td>
</tr>
";
// <TD>...</TD> Template
const string TD = "<td><font face=\"Arial\" size=\"2\"><!--VALUE--></font></td>";
StringBuilder sb = new StringBuilder();
// Table Header
sb.Append("\n<table width=\"100%\" bgcolor=\"#d1d9e4\" cellspacing=\"1\" cellpadding=\"3\">\n");
sb.AppendFormat(heading, headerString);
sb.AppendFormat(" <tr bgcolor=\"#d0d0d0\">\n");
sb.AppendFormat(" {0}\n", TD.Replace("<!--VALUE-->", " <b>Name</b>"));
sb.AppendFormat(" {0}\n", TD.Replace("<!--VALUE-->", " <b>Value</b>"));
sb.Append(" </tr>\n");
// No Body? -> N/A
if(collection.Count == 0)
{
collection = new NameValueCollection();
collection.Add("N/A", "");
}
// Table Body
for(int i = 0; i < collection.Count; i++)
{
sb.AppendFormat(" <tr valign=\"top\" bgcolor=\"{0}\">\n", (i % 2 == 0) ? "white" : "#f4f4f4");
sb.AppendFormat(" {0}\n", TD.Replace("<!--VALUE-->", collection.Keys[i]));
sb.AppendFormat(" {0}\n", TD.Replace("<!--VALUE-->", CleanHtml(collection[i])));
sb.Append(" </tr>\n");
}
// Table Footer
sb.Append("</table>");
return sb.ToString();
}
static private string CollectionToTextTable(string headerString, NameValueCollection collection)
{
// Heading Template
const string heading = "{0}\r\n\r\n";
StringBuilder sb = new StringBuilder();
sb.AppendFormat(heading, headerString);
// No Body? -> N/A
if(collection.Count == 0)
{
collection = new NameValueCollection();
collection.Add("N/A", "");
}
// Table Body
for(int i = 0; i < collection.Count; i++)
{
sb.AppendFormat(" {0} : {1}\r\n", collection.Keys[i], collection[i]);
}
return sb.ToString();
}
static private NameValueCollection BuildCollection(ICollection collection)
{
// Overload for HttpCookieCollection collection.
// Converts HttpCookieCollection to NameValueCollection
if(collection == null)
{
collection = new NameValueCollection();
}
NameValueCollection nvCollection = new NameValueCollection();
IEnumerator en = collection.GetEnumerator();
object entry;
while(en.MoveNext())
{
entry = en.Current;
if(collection is HttpCookieCollection)
{
nvCollection.Add(entry.ToString(), (collection as HttpCookieCollection)[entry.ToString()].Value);
}
// Min
// CANNOT_MAKE_TEST_CONDITION
else if(collection is HttpSessionState)
{
nvCollection.Add(entry.ToString(), (collection as HttpSessionState)[entry.ToString()].ToString());
}
// END-CANNOT_MAKE_TEST_CONDITION
else if(collection is NameValueCollection)
{
if(entry != null)
{
nvCollection.Add(entry.ToString(), (collection as NameValueCollection)[entry.ToString()].ToString());
}
}
else
{
throw new NotSupportedException(collection.GetType().ToString());
}
}
return nvCollection;
}
static private string CleanHtml(string html)
{
// Cleans the string for HTML friendly display
return (html.Length == 0) ? "" : html.Replace("<", "<").Replace("\r\n", "<BR>").Replace("&", "&").Replace(" ", " ");
}
#endregion
}
