Question

in my form I have textField:

                add(new TextField<String>("awayScore", new PropertyModel<String>(value, "awayScore") {

                    private static final long serialVersionUID = 1L;

                    @Override
                    public String getObject() {
                        logger.info("textField");
                        return super.getObject();
                    }
                }));

as you can see I just add logger.

I didnt see anything wrong here but when I run my application I got this error:

java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String
     at org.toursys.web.PlayOffPage$PlayOffForm$2$1$1.getObject(PlayOffPage.java:135)

row 135 contains:

return super.getObject();

I am really confused about it because without overriding this works

UPDATE:

when I edit my code to:

Object value = super.getObject();
logger.error(value.getClass() + "");

this code return:

 class java.lang.Integer

which is really weird because according to compiler this should return String

Answer 1

When you write new PropertyModel<String>(value, "awayScore") you make a promise that the awayScore in your value is a String. The compiler can’t verify your claim and there’s no automatic conversion.

In AbstractPropertyModel the method getObject is defined to return a T which will get replaced by Object. That’s the reason it still works. As soon as you override the method to return String the cast will fail.