Java: Creating a subclass object from a parent object

Question

Newbie Java question. Say I have:

public class Car{
  ...
}

public class Truck extends Car{
  ...
}

Suppose I already have a Car object, h

Answer 1

Would I have to write my own copy constructor? This would have to be updated everytime Car gets a new field...

Essentially, yes - you can't just convert an object in Java.

Fortunately you don't have to write all the code yourself - look into commons-beanutils, specifically methods like cloneBean. This has the added advantage that you don't have to update it every time it gets a new field!