D2Method ClassCastException

paul_wms · 2021-04-15T14:23:52+00:00

There was an error rendering this rich post.

I am trying to invoke the D2CoreMethod from a Java program using the D2Method class. When I call the D2Method.start() method, I get the following exception:

java.lang.ClassCastException: com.documentum.fc.client.DfSysObject___PROXY cannot be cast to com.emc.common.dctm.methods.IC6MethodReturn
	at com.emc.d2.api.methods.D2Method.start(D2Method.java:484)
	at com.emc.d2.api.methods.D2Method.start(D2Method.java:298)
	at com.emc.d2.api.methods.D2Method.start(D2Method.java:275)

This D2Method and D2CoreMethod classes are in the D2-API-20.2.0.jar file. Has anyone used this D2Method successfully in D2 v20.2? This is a new content server and D2 installation.

TIA!

Find more posts tagged with

Documentum

Comments

Karen Weir

Hi @paul_wms , I see that your post hasn't garnered any comments from the community. Have you been able to resolve this on your own, or is it still open for discussion?

paul_wms

I have not resolved that issue. Due to the lack of response, I quit that approach and am invoking the method asynchronously on the server using session.apply(null, "DO_METHOD",...) instead. I don't think the method can be invoked successfully using the D2-API-20.2.0.jar as it is now.

Hicham Bahi

I'm calling D2CoreMethod from a job and it works fine, e.g :

D2CoreMethod.execute(userName, session, job, sysobjList, false, false, true, true, false);

You need to retrieve the job first like this

job = (IDfSysObject) session.getObjectByQualification("dm_job where object_name = 'D2JobCore'");

if (job == null) {

throw new JobException("Failed to retrieve D2JobCore");

}

// seems to be required before calling D2CoreMethod to avoid class cast issues

D2Session.initTBO(session);

benjaminzx

The exaception thrown to indicate that your code has attempted to cast an object to a subclass of which it is not an instance. This means that ClassCastException occurs when you try to cast an instance of an Object to a type that it is not. Type Casting 5 only works when the casted object follows an is a relationship to the type you are trying to cast to.

It is good practice to guard any explicit casts with an instanceof check first:

if (myApple instanceof Fruit) {

Fruit myFruit = (Fruit)myApple;

}

When will be ClassCastException is thrown:

When you try to cast an object of Parent class to its Child class type, this exception will be thrown.
When you try to cast an object of one class into another class type that has not extended the other class or they don’t have any relationship between them

paul_wms

Thanks for your comment, but as stated in the post, the exception occurs in the D2 API code. So, stating the obvious here is not responsive or productive.