cfobject: Java or EJB object

Description

Creates and manipulates a Java and Enterprise Java Bean (EJB) object.

Syntax

<cfobject 
  type = "Java"
  action = "Create"
  class = "Java class"
  name = "object name">

Attributes

Attribute Req/Opt Default Description

type
Optional

Object type:

com

corba

java

(The other object types do not take the type attribute.)

action
Required

Create: Creates a Java or WebLogic Environment object.

class
Required

Java class.

name
Required

String; name for the instantiated component.

Attribute	Req/Opt	Description
type	Optional	Object type: com corba java (The other object types do not take the `type` attribute.)
action	Required	Create: Creates a Java or WebLogic Environment object.
class	Required	Java class.
name	Required	String; name for the instantiated component.

Usage

To call Java CFXs or Java objects, ColdFusion uses a Java Virtual Machine(JVM) that is embedded in the process. You can configure JVM loading, location and settings in the ColdFusion Administrator.

Any Java class available in the class path that is specified in the ColdFusion Administrator can be loaded and used from ColdFusion, using the cfobject tag.

To access Java methods and fields, do the following steps:

Call the cfobject tag, to load the class. See the example code.
Use the init method with appropriate arguments, to call a constructor. For example:
```
<cfset ret = myObj.init(arg1, arg2)>
```

Calling a public method on the object without first calling the init method results in an implicit call to the default constructor. Arguments and return values can be any Java type (simple, array, object). ColdFusion makes the conversions if strings are passed as arguments, but not if they are received as return values.

Overloaded methods are supported if the number of arguments is different.

Calling EJBs

To create and call EJB objects, use the cfobject tag. In the second example below, the WebLogic JNDI is used to register and find EJBHome instances.

Example

<!--- Example of a Java Object his cfobject call loads the class MyClass 
but does not create an instance object. Static methods and fields 
are accessible after a call to cfobject. --->
<cfobject 
  action = "create"
  type = "java"
  class = "myclass"
  name = "myobj">


<!---- Example of an EJB - The cfobject tag creates the Weblogic Environment
object, which is used to get InitialContext. The context object is 
used to look up the EJBHome interface. The call to create() results
in getting an instance of stateless session EJB. --->

<cfobject 
  action = "create"
  type = "java"
  class = "weblogic/jndi/Environment"
  name = "wlEnv">

<cfset ctx = wlEnv.getInitialContext()>
<cfset ejbHome = ctx.lookup("statelessSession.TraderHome")>
<cfset trader = ejbHome.Create()>           
<cfset value = trader.shareValue(20, 55.45)>             
<cfoutput>
   Share value = #value#
</cfoutput>
<cfset value = trader.remove()>

Version 6

Comments are no longer accepted for ColdFusion MX. ColdFusion 8 is the current version.

Comments

Calphool said on May 27, 2004 at 10:17 PM :

It doesn't appear that CFOBJECT has the ability to run the requested java object in a separate JVM from JRUN. If this is the case, then it needs to be addressed, because a misbehaved java object can kill ColdFusion. It doesn't even have to be particularly misbehaved--it need only call "System.exit(0)", and boom! ColdFusion is dead. If we had the option of running a separate JVM instance, this wouldn't be a problem.

ASandstrom said on May 28, 2004 at 8:27 AM :

Have you tried running multiple instances of JRun when you need application isolation?

RSS feed | Send me an e-mail when comments are added to this page | Comment Report

Current page: http://livedocs.adobe.com/coldfusion/6/CFML_Reference/Tags-pt28.htm

CFML Reference