Need help interpreting an RFC Web dynpro exception

[Former Member]

Hi,

The following code shows how I set the content of a wdp model:

Z_Zmm_Tax_Calc2_Input TaxCode2 = new Z_Zmm_Tax_Calc2_Input();
wdContext.nodeZ_ZMM_TAX_CALC2().bind(TaxCode2);

TaxCode2.addItems(new Zzz_Tax_Calc());

It's the last line of the code that causes the exception

When executing the model I get the following.

Error stacktrace:

java.lang.ClassCastException: com.sap.tc.webdynpro.modelimpl.dynamicrfc.WDDynamicRFCException: The Relation must reference ModelClass instances of Type , not of !

at com.sap.tc.webdynpro.modelimpl.dynamicrfc.DynamicRFCModelClass.checkRelatedModelObject(DynamicRFCModelClass.java:727)

at com.sap.tc.webdynpro.modelimpl.dynamicrfc.DynamicRFCModelClass.addRelatedModelObject(DynamicRFCModelClass.java:802)

at com.alum.miromodel.Z_Zmm_Tax_Calc2_Input.addItems(Z_Zmm_Tax_Calc2_Input.java:170)

at com.alum.miro.Cust.initTaxCalc2(Cust.java:911)

Can anyone tell me what it means?

BR

Olof Tronnberg

[Former Member · Accepted solution]

Hi Olof,

Z_Zmm_Tax_Calc2_Input TaxCode2 = new Z_Zmm_Tax_Calc2_Input();

wdContext.nodeZ_ZMM_TAX_CALC2().bind(TaxCode2);

These two lines of code will first create a object of the model node and bind it to the present view s context node.

I thnk this node Z_Zmm_Tax_Calc2_Input() has structures in it. When ur rfc needs inputs we hav to set them as

say

TaxCode2.set<some attribute in the model node>(its value);

If there is a structure

TaxCode2.set<structure name>(new <structure name>);

This is the correct way.

When u say TaxCode2.addItem(); the argument needed is of type Item . IS zzz_tax_calc of that type..

If its not of the type it will throw the classcast exception

AddItem is usually used when we have to add more than instance.

Bind creates one instance of the node and binds it.

I think its a gud practice to stick with bind and set rather than add when it comes to RFC s

Regards

Bharathwaj

[Former Member · Accepted solution]

Seems you are trying to pass a Structure or Table into the RFC.

If the value that you are passing is a Structure, for e.g. passing a single element of a node then you can give it as

TaxCode2.setItem2(new Z<Structure name>());

You can verify in the RFC if the import parameter Item is of type Z<Structure name>.

If the value you are passing is of type table the you can give

TaxCode2.addItem2(new Z<Table name>());

You can verify in the tables tab whether you are passing a table Item of type Z<Table name>.

revert for further clarification.

regards

Noufal

[Former Member · Accepted solution]

Hello everyone,

...and thank you for all your answers. It really taught me alot!

It seems as though the exception was caused by the "model reimport" that I made earlier. After having restarted J2EE engine the problems with the classcast exception went away.

Regards

Olof Tronnberg

[Former Member]

I am no expert in this area, but perhaps your code should be something like

TaxCode2.set<RelationName>( new Zzz_Tax_Calc() );

instead of

TaxCode2.addItems(new Zzz_Tax_Calc());

<RelationName> is the name of the parent/child-relation between the input node and the structured parameter (double-arrow symbol).

See "Inside Web Dynpro", chapter 10.7.1

Only a guess...

Armin

[Former Member]

for(all elements to be added to the import table)

{

<ModelClass of Rfc Import Table> objectName = new <ModelClass>;

objectName.set<Attribute>;

.

.

TaxCode2.add<Rfc Import TableName>(objectName);

}

In your case, I feel that 'Zzz_Tax_Calc' is the Rfc Import Table

Hope I'm right.

[Former Member]

You are adding wrong class to relation.

However, compiler allows you to do this. Then you are either need to re-generate model (because of changes in back-end) or resolve problems with class loaders (very rare case with typical Adaptive RFC model)

VS

[Former Member]

Hi,

Looks like problem with the parameter that you are passing to the addItems method.

Try this

TaxCode2.addItems(new Z_Zmm_Tax_Calc2());

Regards, Anilkumar