Programming ColdFusion

Chapter 9. Error and Exception Handling

Structured exception handling lets you gracefully catch and handle exceptions that occur in your ColdFusion applications. Exceptions can include anything from a page timeout or a missing file to a database error or a problem with an external object. Using the techniques discussed in this chapter, you can build extremely robust exception-handling capabilities into your ColdFusion applications.

There are a number of different levels at which you can handle exceptions and errors in a ColdFusion application. At the most basic level, you can use the CFTRY and CFCATCH tags in a template, to test for and trap exceptions right where they occur. With the CFTHROW tag, you can also define, throw, and catch custom exceptions in your application.

Of course, catching every exception when it occurs can become quite tedious, so ColdFusion provides a couple of different mechanisms for handling exceptions at a higher level. With the CFERROR tag, you can define generic error handlers for different kinds of errors. The CFERROR tag is normally used in the Application.cfm template, so that error handling occurs in the context of the Web Application Framework. This ability to provide “catch all” error handling for an application is quite convenient and powerful.

In addition, as of ColdFusion 4.5, a site administrator can set up error and exception handling at the server level, using the ColdFusion Administrator. We’ll cover all these different techniques for error ...