Clearing doubts about the builder pattern

Question

I am learning about the builder pattern, and so far I understood that, it is a great alternative to the commonly patterns used for initialization:

• Telescopi

Answer 1

What does using a builder here actually gain you?

Nothing as far as I can see: you could just create a new Product and use the getters and setters on it directly. If you have a simple POJO then there is absolutely nothing wrong with:

Product p=new Product();
p.setColour("Black");
p.setPrice(11);
doSomethingWith(p);

Saving a few characters of typing is IMHO not worth introducing a new class / builder abstraction.

Builders are more useful in situations like the following:

• You want to create an immutable object (and hence can't use setters)
• If you have complicated factory logic that cannot easily be expressed with simple getters and setters or that you want to re-use in different ways
• (Occasionally) when you want to have different parts of the code base configure different aspects of the builder for some reason.