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Chapter 33: Integrating J2EE and Java Elements in CFML Applications
To disable automatic class loading of your classes, put the classes in the JVM classpath. Classes
located on the JVM classpath are loaded once per server lifetime. To reload these classes, stop and
restart ColdFusion MX.
Note:
Because you put tag libraries in the
web_root
/WEB-INF/lib directory, ColdFusion
automatically reloads these libraries if necessary when you import the library.
About GetPageContext and the PageContext object.
Because ColdFusion pages are J2EE servlet pages, all ColdFusion pages have an underlying Java
PageContext object. CFML includes the
GetPageContext
function that you can then use in your
ColdFusion page.
The PageContext object exposes a number of fields and methods that can be useful in J2EE
integration. In particular, it includes the
include
and
forward
methods that provide the
equivalent of the corresponding standard JSP tags.
This chapter describes how to use the
include
and
forward
PageContext methods for calling
JSP pages and servlets. It does not discuss the PageContext object in general. For more
information on the object, see Java documentation. You can find the Javadoc description of this
class at http://java.sun.com/j2ee/sdk_1.3/techdocs/api/javax/servlet/jsp/PageContext.html.
About CFML variables and Java variables
Because ColdFusion variables are case-independent and Java variables are case-dependent, you
must be careful about variable names. Use the following rules and guidelines when sharing data
between ColdFusion and Java code, including JSP pages and servlets:
Rules
•
If you use mixed case variables, all variable names must be unique, independent of case. For
example, you must not have two Java variables, MyVariable and MYVARIABLE. ColdFusion
cannot distinguish between the two.
•
If you share Request scope variables between a CFML page and a JSP page or servlet, all shared
Request scope variable names
must
be all-lowercase in the JSP page or servlet. Mixed case or all-
uppercase variables will cause null pointer exceptions if CFML refers to these variables.
•
If you share Application or Session scope variables between a CFML page and a JSP page or
servlet and use a named ColdFusion application (the common usage), the variables on the JSP
page or servlet are case-independent.
•
If you share the Application or Session scope variables between a CFML page and a JSP page
or servlet, and use an
unnamed
ColdFusion application, the variable names in the JSP page or
servlet
must
be all lowercase.
•
When you specify a class name in the
cfobject
tag or
CreateObject
function, the name
must be case-correct.
Guidelines
•
You can prevent problems by consistently using all-lowercase variable names.
•
In your CFML, use the same case as you do in your Java or JSP. Doing so does not change how
the application works, but does help prevent confusion.
Содержание COLDFUSION MX 61-DEVELOPING COLDFUSION MX
Страница 1: ...Developing ColdFusion MX Applications...
Страница 22: ...22 Contents...
Страница 38: ......
Страница 52: ...52 Chapter 2 Elements of CFML...
Страница 162: ......
Страница 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Страница 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Страница 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Страница 266: ......
Страница 314: ...314 Chapter 14 Handling Errors...
Страница 344: ...344 Chapter 15 Using Persistent Data and Locking...
Страница 349: ...About user security 349...
Страница 357: ...Security scenarios 357...
Страница 370: ...370 Chapter 16 Securing Applications...
Страница 388: ...388 Chapter 17 Developing Globalized Applications...
Страница 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Страница 410: ......
Страница 426: ...426 Chapter 19 Introduction to Databases and SQL...
Страница 476: ...476 Chapter 22 Using Query of Queries...
Страница 534: ...534 Chapter 24 Building a Search Interface...
Страница 556: ...556 Chapter 25 Using Verity Search Expressions...
Страница 558: ......
Страница 582: ...582 Chapter 26 Retrieving and Formatting Data...
Страница 668: ......
Страница 734: ...734 Chapter 32 Using Web Services...
Страница 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Страница 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Страница 788: ......
Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...