MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

Page: 288 / 860

288 Chapter 14: Handling Errors
About ColdFusion exceptions
You can categorize ColdFusion exceptions in two ways:
•
When they occur
•
Their type
When exceptions occur
ColdFusion errors can occur at two times, when the CFML is compiled into Java and when the
resulting Java executes, called runtime exceptions.
Compiler exceptions
Compiler exceptions are programming errors that ColdFusion identifies when it compiles CFML
into Java. Because compiler exceptions occur before the ColdFusion page is converted to
executable code, you cannot handle them on the page that causes them. However, other pages can
handle these errors. For more information, see
“Handling compiler exceptions”
Runtime exception
A runtime exception occurs when the compiled ColdFusion Java code runs. It is an event that
disrupts the application’s normal flow of instructions. Exceptions can result from system errors or
program logic errors. Runtime exceptions include:
•
Error responses from external services, such as an ODBC driver or CORBA server
•
CFML errors or the results of
cfthrow
or
cfabort
tags
•
Internal errors in ColdFusion MX
ColdFusion exception types
ColdFusion exceptions have types that you specify in the
cferror
,
cfcatch
, and
cfthrow
error-
handling tags. A
cferror
or
cfcatch
tag will handle only exceptions of the specified type. You
identify an exception type by using an identifier from one (or more) of the following type
categories:
•
Basic
•
Custom
•
Advanced
•
Java class
Note: Use only custom error type names and the
Application
basic type name in
cfthrow
tags. All
other built-in exception type names identify specific types of system-identified errors, so you should
not use them for errors that you identify yourself.