Before using interactive debuggers became the norm, programmers typically debugged their programs by inserting output statements in their programs to indicate information such as variable values and control paths taken. Often, when a new platform emerges, this technique comes back into vogue while programmers wait for more sophisticated debugging technology to develop for the platform.
If you need to debug a Java CFX tag while running against a live production server, this is the technique you must use. In addition to outputting debugging text using the Response.write method, you can also call your Java CFX tag with the debug="On" attribute. This attribute flags the CFX tag that the request is running in debug mode and therefore should output additional extended debugging information. For example, to call the HelloColdFusion CFX tag in debugging mode, use the following CFML code:
<cfx_HelloColdFusion name="Robert" debug="On">
To determine whether a CFX tag is invoked with the debug attribute, use the Request.debug method. To write debugging output in a special debugging block after the tag finishes executing, use the Response.writeDebug method. For information on using these methods, see ColdFusion Java CFX Reference in CFML Reference.