validation in gui and error handling

hi,
I have a gui application which asks the user to input two numerical
values in text fields.
One must be an integer and the other should be a decimal . Also the
user is supposed to select an image file using a filechooser.I would
like to display proper error messages on a text area of the gui if the
selection is wrong or if the textfield inputs are improper.
I figured out that these scenarios can occur.
1.user doesn't select any file
2.user selects a file which is not an image file.
3.user doesnot enter any value in textfields or leaves one blank.
4.user enters invalid string in textfield which cannot be converted to
proper data type(ie int or double).

So,I thought I would do the validation in the model and let controller
ask the view to display appropriate messages.
I made a class ResultData to pass the message and values from model to
the controller.

<code>
class ResultData{
    private boolean success;
    private String someName;
    private String resultMessage;
    private double someValue;
    public ResultData(boolean s,String n,double sv,String m){
        success = s;
        someName = n;
        someValue = sv;
        resultMessage = m;
    }
    //getters and setters...
}

</code>

In the model I have a processSelections() which accepts user input and
processes them

<code>
public ResultData processSelections(String intFieldInput,String
decimalFieldInput,String selectedFileName ){
    ResultData rdata;
    int someInteger;
    double someDecimal;
    try{
        validateSelectedFile(selectedFileName);
        someInteger = new Integer(intFieldInput).intValue();
        someDecimal = new Double(decimalFieldInput).doubleValue();
        rdata =
doSomeWorkwithUserInput(selectedFileName,someInteger,someDecimal);

    }catch(Exception e){
        rdata = new ResultData(false,null,0,e.getMessage());
        return rdata;
    }

}

private void validateSelectedFile(String fileName)throws Exception{
    if (fileName.length() == 0){
        throw new RuntimeException("select a file");
    }
    if (!isAnImageFile(faceimagename)){
        throw new RuntimeException("select an imagefile");
    }
}
....
</code>

The controller gets a ResultData object containing true value for
success,correct result values and a message if everything went ok.
If there were any exceptions during the validation or in
doSomeWorkwithUserInput() ,the ResultData object will have
success=false, someName=null ,0 for numerical value and the correct
error description in message .controller can ask view to display these
results.

This is the first time I am doing a gui app in java.I am not sure this
is the correct way of dealing with the validations and error
displays.If someone can point me to the right way ,it will help me a
lot.
thanks in advance,
harry