MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

Page: 737 / 860

About ColdFusion, Java, and J2EE 737
•
JSP comments
Instead, you use CFML comments. (ColdFusion ignores JSP comments
and passes them to the browser.)
•
Standard JSP tags Such as jsp:plugin, unless your J2EE server provides access to these tags
in a JAR file. Instead, you use ColdFusion tags and the PageContext object.
About ColdFusion and Servlets
Some Java servlets are not exposed as JSP pages; instead they are Java programs. You can
incorporate JSP servlets in your ColdFusion application. For example, your enterprise might have
an existing servlet that performs some business logic. To use a servlet, the ColdFusion page
specifies the servlet by using the ColdFusion
GetPageContext
function.
When you access the servlet with the
GetPageContext
function, the ColdFusion page shares the
Request, Application, and Session scopes with the servlet, so you can use these scopes for shared
data.
ColdFusion pages can also access servlets by using the
cfhttp
tag, use the servlet URL in a
form
tag, or access an SHTML page that uses a
servlet
tag.
Note: The cfservlet tag, which provides access to servlets on JRun servers, is deprecated for
ColdFusion MX.
About ColdFusion and Java objects
Java objects include the following:
•
Standard Java classes and methods that make up the J2EE API
•
Custom-written Java objects, including the following:
■
Custom classes, including JavaBeans
■
Enterprise JavaBeans
ColdFusion pages use the
cfobject
tag to access Java objects.
ColdFusion MX searches for the objects in the following order:
1
The ColdFusion Java Dynamic Class Load directories:
■
Java archive (.jar) files in web_root /WEB-INF/lib
■
Class (.class) files in web_root /WEB-INF/classes
ColdFusion reloads classes from these directories, as described in the next section, “About class
loading” .
2
The classpath specified on the ColdFusion MX Administrator JVM and Java Settings page.
3
The default JVM classpath.
About class loading
ColdFusion dynamically loads classes that are either .class files in the web_root /WEB-INF/classes
directory or in JAR files in the web_root /WEB-INF/lib directory. ColdFusion checks the time
stamp on the file when it creates an object that is defined in either directory, even when the class
is already in memory. If the file that contains the class is newer than the class in memory,
ColdFusion loads the class from that directory.
To use this feature, make sure that the Java implementation classes that you modify are not in the
general JVM classpath.