A helper class that contains only the logic to fill the object
is called a Factory Class. It seems that this is what you need.
Also, take a look at Dependency Injection.
bruno conde
2009-12-16 14:04:34
+3
A:
+1
A:
Where does this information come from? Is it hardcoded/consistent? Use the Object's constructor. Is it variable or does it come from a datastore? Use the DAO pattern.
BalusC
2009-12-16 14:22:45
it comes from a DataStore.
EugeneP
2009-12-16 14:38:19
Here's a kickoff tutorial about the DAO pattern: http://balusc.blogspot.com/2008/07/dao-tutorial-data-layer.html
BalusC
2009-12-16 14:58:03
+1
A:
Joshua Bloch discusses Static Factories and the Builder pattern in this excerpt from the second edition of his book Effective Java.
trashgod
2009-12-16 14:26:08
It seems to me that you answered my question. But it proves that the extraction/getting a reference logic should stay within the object. Is that true?
EugeneP
2009-12-16 14:42:24
Yes, in the sense that the cited patterns are ways to impose an internally consistent object state. The manner in which this is achieved is an implementation detail. As your source is a DataStore, the DAO pattern suggested by BalusC is a way to minimize the coupling mentioned in your original question.
trashgod
2009-12-16 15:22:18
A:
Regarding your last phrase: 'So I can call it a factory, but would it really be what they called "A Factory pattern"?'
IMHO, patterns are just food for thought. Don't worry too much if whatever you're doing fits the exact textbook definition (which is disputed anyway) or not. :-)
Eli Acherkan
2009-12-16 14:37:53