By default, ColdFusion generates its own error messages when it encounters errors. In addition, it provides a variety of tools and techniques for you to customize error information and handle errors when they occur. You can use any of the following error-management techniques.

• Specify custom pages for ColdFusion to display in each of the following cases:
  • When a ColdFusion page is missing (the Missing Template Handler page)
  • When an otherwise-unhandled exception error occurs during the processing of a page (the Site-wide Error Handler page)

  You specify these pages on the Settings page in the Server Settings page in the ColdFusion Administrator; for more information, see the ColdFusion Administrator Help.

• Use the cferror tag to specify ColdFusion pages to handle specific types of errors.
• Use the cftry, cfcatch, cfthrow, and cfrethrow tags to catch and handle exception errors directly on the page where they occur.
• In CFScript, use the try and catch statements to handle exceptions.
• Use the onError event in Application.cfc to handle exception errors that are not handled by try/catch code on the application pages.
• Log errors. ColdFusion logs certain errors by default. You can use the cflog tag to log other errors.

The remaining sections in this chapter provide the following information:

• The basic building blocks for understating types of ColdFusion errors and how ColdFusion handles them
• How to use the cferror tag to specify error-handling pages
• How to log errors
• How to handle ColdFusion exceptions