RE: More on my copyProperties/EJB woes

[Deadman, Hal]

Although copyProperties to an entity bean might work, it would be making a call through the remote interface each time it sets a property on the entity bean. I think it's good practice to minimize the number of remote calls made to an EJB. (Often in practice the calls are not really remote but it's good to pretend like they could be.) That would allow you to separate your JSPs and EJBs or use Tomcat for JSPs and Weblogic for EJBs. Normally instead of calling set methods on an entity bean from the web tier, I call a session bean and pass a simple JavaBean to it that isn't tied to Struts, often the bean may have been nested in an ActionForm. Then I have a create or an update method in the entity bean that accepts the JavaBean as an argument. I don't always put all the getters and setters for individual fields in the entity bean remote interface unless I need them.

 

Sorry if this isn't helpful, I would be interested to hear if anyone disagrees.

 

Hal

 

 -----Original Message-----
From: Bryan Field-Elliot [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, March 13, 2001 12:06 AM
To: [EMAIL PROTECTED]
Subject: More on my copyProperties/EJB woes

I've been tearing apart my problems using copyProperties in an EJB environment;

The scenario is that I am using PropertyUtils.copyProperties to copy everything FROM a simple bean, TO an EJB entity bean.

Earlier tonight I thought that the hangup was over the destination bean, perhaps because it was an EJB remote interface. But my digging turns up that this isn't the case.

The exception is during the getting of the source properties (from my simple bean), and it never even gets to the setting of the destination property.

I extracted a small piece of code from copyProperties and am executing it directly:

// pv is my simple bean, and "name" is a String property within in, which has a getter and a setter method.
PropertyDescriptor descriptor;

// Following two lines are key:
descriptor = PropertyUtils.getPropertyDescriptor(pv, "name");
//descriptor = new PropertyDescriptor("name", pv.getClass());

Method readMethod = descriptor.getReadMethod();
Object value = readMethod.invoke(pv, new Object[0]);


When I use the first of the two "descriptor = " lines (thereby making use of Struts), I get the following exception on the invoke() line:

Name: java.lang.IllegalArgumentException
Message: object is not an instance of declaring class
Stack: java.lang.IllegalArgumentException: object is not an instance of declaring class
at java.lang.reflect.Method.invoke(Native Method)

However, when I use the second of the two "descriptor = " lines (thereby using standard Java SDK reflection), the invoke() line executes correctly.

Any help would be appreciated.

This is using Struts 1.0 beta-1 (binaries).

Regards,
Bryan