Complete example using custom errors and write errors to the Event logWriting to the Windows 2000 Event Log is a powerful feature of the ASP.NET and .NET framework. For those individuals who work in a large company and want to make track application errors, writing to the event log is a must! There wasn't any complete demos actually showing from A - Z how this was setup for the novice/common developer like me. Most novice developers need to be spoon fed how things are done the first time, once they see a simple example, they'll understand how the process works! This example is my reference how to make a complete application from A - Z setup and fail to understand how it works. |
| Step 1First of all the steps I followed was to create a simple web called eventlog. I also created the application rootso the global.asax file would fire.
Step 2I opened the global web.config file and turned on custom errors. Path to this is c:winntmicrosoft.netframework.. There are 3 choices available currently On, Off and RemoteOnly. From attending the conference, the recommended was RemoteOnly. This means anyone not on the console of the machine will see a friendly error and not the real thing. For this example I chose On. You also could leave the global web.config file custom errors turned off and configure at application level's web.config Either way works just fine.
web.config -- this file is placed in the root of the eventlog application root. <configuration>
<system.web>
<customErrors mode="On" defaultRedirect="/eventlog/customerrorpage.aspx">
<error statusCode="404" redirect="/eventlog/404Page.aspx"/>
<error statusCode="403" redirect="/eventlog/403page.aspx"/>
</customErrors>
</system.web>
</configuration> Step 3The next few items are just to create sample pages to make the application complete. I created a web.config, global.asax, Default.aspx page, and three sample error pages. 404page.aspx, 403page.aspx and customerrorpage.aspx page.
Here are those pages code for all pages. Global.asax Page - This uses the Application_OnError event to capture stuff if an error happens <%@ Import Namespace="System" %>
<%@ Import Namespace="System.Diagnostics" %>
<script language="VB" runat=server>
Public Sub Application_OnError(Sender as Object, E as EventArgs)
'Captures the error and converts to a string
dim LastError as Exception = Server.GetLastError()
Dim ErrMessage as String = LastError.toString()
Dim LogName As String = "MyLog"
Dim Message As String = "Url " & Request.Path & " Error: " & ErrMessage
' Create Event Log if It Doesn't Exist
If (Not EventLog.SourceExists(LogName)) Then
EventLog.CreateEventSource(LogName, LogName)
End if
Dim Log as New EventLog
Log.Source = LogName
'These are the five options that will display a different icon.
'The numbers are just to show the order. These aren't required
Log.WriteEntry(Message, EventLogEntryType.Information, 1)
' Log.WriteEntry(Message, EventLogEntryType.Error, 2)
' Log.WriteEntry(Message, EventLogEntryType.Warning, 3)
' Log.WriteEntry(Message, EventLogEntryType.SuccessAudit, 4)
' Log.WriteEntry(Message, EventLogEntryType.FailureAudit, 5)
End Sub
</script> Default.aspx page
<% @Language="VB" %>
<script language="VB" runat=server>
Sub Page_Load(Sender As Object, E As EventArgs)
If IsPostBack Then
'Declare all variables
dim x as integer
dim y as integer
dim z as integer
'set x and y to values to be divided by zero
x = 1
y = 0
'perform the division by zero to raise the error
z = x/y
End Sub
</script> <html>
<head>
</head>
<body>
<form method="post" action="eventlog.aspx" name="form1" id="number">
<asp:Button id="abutton" type="submit" text="Click Me to generate an error" runat="server" />
</form>
</body>
</html> Customerrorpage.aspx <html>
<head></head>
<body>
<h1>custom error page</h1>
</body>
</html>
404page.aspx --Capture all 404(Not Found pages) <html>
<head></head>
<body>
<h1>404 error page</h1>
</body>
</html>
403page.aspx --Capture all 403(Restricted pages) <html>
<head></head>
<body>
<h1>403 error page</h1>
</body>
</html> Step 4After all webs are created, web.config files in place. It was time to test out the application to see if it works. Type in http://localhost/eventlog/default.aspx file, this will display a button. Click it and see if this actually creates the log and writes the information to the event log. Actually only the custom error page will be displayed, the eventlog.aspx page will error and be transfered to the customerrorpage.aspx. The URL will be something like this.
http://localhost/eventlog/customerrorpage.aspx?aspxerrorpath=/eventlog/eventlog.aspx The page will appear like this Step 5. Verify the log was created and entry was placed in that log. The example shows a Critical error message. You also can show informational or yellow warning messages. For this example we showed all 5 possible entries
Open the Error and view the message. If the customerror wasn't turned on, this error would have shown up in the browser instead of the eventlog. Not pretty!!
Thats it! This was a high-level example with examples but hopefully helps in understanding how a sample application and using the new Error-handling features of ASP.NET... Enjoy!!
Parameters for WriteEntry Method- source
- The source by which the application is registered on the specified computer.
- message
- The string to write to the event log.
- type
- One of the EventLogEntryType values.
- eventID
- The application-specific identifier for the event.
- category
- The application-specific subcategory associated with the message.
- rawData
- An array of bytes that holds the binary data associated with the entry.
Five possible types of Event log messages. These show the different types of icons | Member Name | Description |
|---|
| Error | An error event. This indicates a significant problem the user should know about; usually a loss of functionality or data. | | FailureAudit | A failure audit event. This indicates a security event that occurs when an audited access attempt fails; for example, a failed attempt to open a file. | | Information | An information event. This indicates a significant, successful operation. | | SuccessAudit | A success audit event. This indicates a security event that occurs when an audited access attempt is successful; for example, logging on successfully. | | Warning | A warning event. This indicates a problem that is not immediately significant, but that may signify conditions that could cause future problems. |
|
| DISCLAIMER: The content provided in this article is not warranted or guaranteed by Developer Shed, Inc. The content provided is intended for entertainment and/or educational purposes in order to introduce to the reader key ideas, concepts, and/or product reviews. As such it is incumbent upon the reader to employ real-world tactics for security and implementation of best practices. We are not liable for any negative consequences that may result from implementing any information covered in our articles or tutorials. If this is a hardware review, it is not recommended to open and/or modify your hardware. |
More ASP.NET Articles
More By aspfree  developerWorks - FREE Tools!
|
This demonstration gives you an overview of IBM® Rational® Build Forge Express Edition, a global offering that provides a framework to automate and execute software processes. Rational Build Forge provides a software assembly line that can support all of your tools, technologies, and platforms so you can achieve a repeatable, reliable, and traceable build and release process.
FREE! Go There Now!
| | | |
<a href="http://zeus.developershed.com/shonuff.php?blackbird=3853&zoneid=442&source=&dest=http%3A%2F%2Fwww.ibm.com%2Fdeveloperworks%2Fspaces%2Fjazz%3FS_TACT%3D105AGY31%26S_CMP%3DDEVSHED&ismap="><img src="http://images.devshed.com/corp/img/news/jazz01.gif" alt="developerWorks Jazz space" align="left"></a>You've heard the buzz about Jazz... want to know more about it from a developer's perspective? Check out the Jazz space on developerWorks. This space is an up-to-date resource for developers, including technical information about Jazz and products built on Jazz, like Rational Team Concert Express. The Jazz space includes content from a wide variety of sources, including links, feeds, and comments from experts.
FREE! Go There Now!
| | | |
Build secure Web services with transport-level security using IBM Rational Application Developer V7 and IBM WebSphere Application Server V6.1. Follow this three-part series for step-by-step instructions about how to develop Web services and clients, configure HTTP basic authentication, and configure HTTP over SSL (HTTPS). This first part of the series walks you through building a Web service for a simple calculator application. You generate and test two different types of Web services clients: a Java Platform, Enterprise Edition (Java EE) client and a stand-alone Java client. You also handle user-defined exceptions in Web services.
FREE! Go There Now!
| | | |
WebSphere Process Server delivers a unique integration framework that simplifies existing IT resources. Often, as IT assets grow to support business demand, so too does their complexity and manageability. In this webcast, we’ll discuss how WebSphere Process Server helps deliver an SOA infrastructure that provides a common model to orchestrate, mediate, connect, map, and execute the underlying IT functions. Discover how WebSphere Process Server simplifies integration of business processes by leveraging existing IT assets as reusable services without the complexities of traditional integration methodologies.
FREE! Go There Now!
| | | |
Visit IBM developerWorks to download a free trial version of WebSphere Business Modeler Advanced V6.1.1, IBM’s premier business process modeling and analysis tool for business users that offers process modeling, simulation, and analysis capabilities. IBM WebSphere Business Modeler helps you visualize, understand, and document business processes for continuous improvement.
FREE! Go There Now!
| | | |
Visit IBM developerWorks to download a free trial version of IBM Rational Business Developer V7.1. Rational Business Developer offers rapid and simplified development of business applications and services through Enterprise Generation Language (EGL) tools, generating Java or mainframe solutions while shielding developers from technical complexities.
FREE! Go There Now!
| | | |
Join this Rational Talks to You teleconference on December 4 at 1:00 pm ET to discuss how Rational Method Composer can help meet your compliance objectives. Get your questions answered!
FREE! Go There Now!
| | | |
As businesses grow increasingly dependent upon Web applications, these complex entities grow more difficult to secure. Most companies equip their Web sites with firewalls, Secure Sockets Layer (SSL), and network and host security, but the majority of attacks are on applications themselves – and these technologies cannot prevent them. This paper explains what you can do to help protect your organization, and it discusses an approach for improving your organization’s Web application security.
FREE! Go There Now!
| | | |
Whether you are creating new applications or modifying existing ones, managing integration of new components with traditional z/OS elements is a critical part of building and deploying modern applications. Listen to this webcast to see how IBM can help you optimize your development process using an IDE like Rational Developer for System z that integrates with management tools, such as ClearCase to manage your application development on mainframes.
FREE! Go There Now!
| | | |
The Eclipse community is constantly working to extend Eclipse's functionality. In this webcast, learn about some of the most important and feature-rich projects under development. From multi-language support to plug-in development, tune in to see what Eclipse is capable of now.
FREE! Go There Now!
| | | |
All FREE IBM® developerWorks Tools!
| |
