Java: Persistence Class with toDTO method categorized as adapter pattern?

Question

If i have an Persistence class which implements a method "toDTO" and this method return a POJO representing the object, will this be categorized as an adapter pattern?

Please note, that this is not a question of the implementation as such, but rather in which way it would be categorized.

score 1 · Accepted Answer · answered Jan 11 '13 at 14:34

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If the DTO uses the live state of the Persistence object then this may be classified as an adapter; if it makes a defensive copy of the data, discarding the original, then it is not an adapter.

answered Jan 11 '13 at 14:34

Marko Topolnik

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Im not sure i understand your point, would it be a bother to clarify a little? (sorry for the late reply) i mean its a pojo so it would always be regarded as a defensive copy, or am i misunderstanding? – Andy Vidkjær Jan 18 '13 at 21:44
If the DTO doesn't hold a reference to the persistence object, then there can definitely be no word of the *Adapter* pattern at work. – Marko Topolnik Jan 18 '13 at 21:56
Well in my case, it will hold an id referencing the object in db. so that would definitely be adapter pattern? – Andy Vidkjær Jan 18 '13 at 22:06
That's an extralinguistic reference, it has nothing to do with OOP patterns. – Marko Topolnik Jan 18 '13 at 22:09

score 0 · Answer 2 · edited May 23 '17 at 11:48

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Note that DTO is usually classified as a pattern on itself. See Fowler's Patterns of Enterprise Application Architecture.

See also this SO question for discussion about DTO being an anti-pattern.

edited May 23 '17 at 11:48

Community

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answered Jan 11 '13 at 14:48

brabec

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Java: Persistence Class with toDTO method categorized as adapter pattern?

2 Answers2