Re: General rule for constructors
pek wrote:
Hello, I've been reading lately Effective Java and Josh Bloch suggests
more than once to avoid using the default public constructors in order
to solve particular problems. More specifically, Item 1 says "Consider
static factory methods instead of constructors" or Item 2 "Consider a
builder when faced with many constructors" etc etc..
While all these paradigms are great (I was stunned when reading the
Builder pattern) I do feel that his general advice for constructors is
thinking like method visibility (start from private and build up to
public):
First try to see if all other are relevant to your problem and then,
as a final solution, create a public constructor.
Is this the way I should be thinking? Is creating a public constructor
the least desired way of constructing an object? Or are these
solutions good only for the problems they specifically solve?
Not that I'm against it. On the contrary, his solutions blow my mind
away (obviously, I'm not the guy you would call an advanced
programmer).
Note that consider != always.
There are some classes where using a constructor ties a lot
of your code to an implementation that you may want to
change.
JAXP W3C DOM Document is a good example of an alternative
approach and why it is beneficial.
You could argue that Spring is fundamentally based on the
concept.
So consider it and and chose it when it makes sense.
Arne
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