Do i need to implement the interface from parent class again

Question

I have a interface ShippingProduct and 2 classes ShippingProductStandard, ShippingProductGurtmass.

The class ShippingProductStandard implements the interface ShippingProduct.

public class ShippingProductStandard implements ShippingProduct {
...
}

Now i want that, the class ShippingProductGurtmass extends ShippingProductStandard and implements ShippingProduct. Do i need to implement the interface ShippingProduct like that:

public class ShippingProductGurtmass extends ShippingProductStandard implements ShippingProduct {
...
}

Or do i only need to extend the class ShippingProductStandard and it will implement the interface ShippingProduct from the parent class automatic?

public class ShippingProductGurtmass extends ShippingProductStandard{
...
}

Duplicate: http://stackoverflow.com/a/5668477/6507689. Look on stack first before posting of question~. — R. Zagórski, Jun 28 '16 at 08:10
@R.Zagórski Thanks I was looking for one. FYI, prefer to flag as duplicate, this is the preferred to way to link to a potential duplicate. — Tunaki, Jun 28 '16 at 08:17

Nuri Tasdemir · Answer 1 · 2016-06-28T09:57:11.347

1

Just extend the class ShippingProductStandard and it will implement the interface ShippingProduct from the parent class automatically. You may override those methods if you like.

edited Jun 28 '16 at 09:57

answered Jun 28 '16 at 08:11

Nuri Tasdemir

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score 1 · Accepted Answer · answered Jun 28 '16 at 08:11

there is no need to write a relationship like this

public class ShippingProductGurtmass extends ShippingProductStandard implements ShippingProduct {
...
}

you can use only this code to call the overrided/implemented methods (in ShippingProductGurtmass) of Interface ShippingProduct

public class ShippingProductGurtmass extends ShippingProductStandard{
...
}

Relation hierarchy is automatically generated. You can Imagine it like as the java Concept says Object is a parent Class for all classes written in Java.

Do i need to implement the interface from parent class again

2 Answers2