Handling exceptions between tiers

Question

I currently have this issue I can't resolve. I have a project in JDeveloper, using ADF. When an exception (Throwable) occur somewhere in Model tier, I can't catch it in View tier. Let me explain it better:

In View, I have Transaction.java where

public void save(){
     try{ 
         Boolean res= (Boolean) context.get("res"); //value obtained from front-end
         OperationBinding op = this.getBindings().getOperationBinding("methodThatThrowsException"); 
         op.getParamsMap().put("res", res);
         op.execute();//line that should throw exception
     }catch(ClassCastException cce){
          showMessage(cce.getMessage()); //pop up with a description of the exception
}

Then, in Model tier:

public void methodThatThrowsException(Boolean res) throws ClassCastException {
     try{ 
         Object obj = res;
         Integer badCoding = (Integer) obj; //line that throws exception
     }catch(ClassCastException e){
           //clean-up code
        }
}

methodThatThrowsException will throw a ClassCastException but it is not caught in save method. I don't know what's wrong. I even tried and failed adding in save after op.execute();

if(!op.getErrors().isEmpty()){
for(Throwable t : op.getErrors()){
    if (t instanceof Exception){
        Exception e = (Exception) t;
        if (e instanceof RuntimeException)
            RuntimeException re = (RuntimeException) e;
            if(re instanceof ClassCastException)
                throw t;
    }

}

But with this horrible workaround, t is never thrown because it's a JBOException, not a ClassCastException when it's on View tier.

What can I do? Any suggestion works for me right now. Thanks in advance.

Answer 1

Binding layer's exception handling is counter-intuitive for anyone familiar with java:

Boolean res= (Boolean) context.get("res"); //value obtained from front-end
perationBinding op = this.getBindings().getOperationBinding("methodThatThrowsException"); 
op.getParamsMap().put("res", res);
op.execute();//line that should throw exception
//grab the exception this way
op.getErrors()