What is the design pattern that Wrapper Classes use in Java?
up vote
11
down vote
favorite
I have found an old post on StackOverflow which does not clarify my understanding about the design patterns that are used by Wrapper Classes:
What is a wrapper class? Moreover, on reading from Wikipedia I am not getting any clear information.
Does a Wrapper Class really use any design pattern or not?
If it is using a pattern, then which pattern is it out of these: Decorator Pattern
, Facade Pattern
or Adapter Pattern
?
design-patterns adapter decorator wrapper facade
New contributor
add a comment |
up vote
11
down vote
favorite
I have found an old post on StackOverflow which does not clarify my understanding about the design patterns that are used by Wrapper Classes:
What is a wrapper class? Moreover, on reading from Wikipedia I am not getting any clear information.
Does a Wrapper Class really use any design pattern or not?
If it is using a pattern, then which pattern is it out of these: Decorator Pattern
, Facade Pattern
or Adapter Pattern
?
design-patterns adapter decorator wrapper facade
New contributor
2
My take on it is that a wrapper class is no pattern, it just wraps existing classes. Patterns like Decorator, Facade and Adapter often make use of a wrapper class. But that's only my opinion!
– Nordiii
Nov 15 at 8:43
add a comment |
up vote
11
down vote
favorite
up vote
11
down vote
favorite
I have found an old post on StackOverflow which does not clarify my understanding about the design patterns that are used by Wrapper Classes:
What is a wrapper class? Moreover, on reading from Wikipedia I am not getting any clear information.
Does a Wrapper Class really use any design pattern or not?
If it is using a pattern, then which pattern is it out of these: Decorator Pattern
, Facade Pattern
or Adapter Pattern
?
design-patterns adapter decorator wrapper facade
New contributor
I have found an old post on StackOverflow which does not clarify my understanding about the design patterns that are used by Wrapper Classes:
What is a wrapper class? Moreover, on reading from Wikipedia I am not getting any clear information.
Does a Wrapper Class really use any design pattern or not?
If it is using a pattern, then which pattern is it out of these: Decorator Pattern
, Facade Pattern
or Adapter Pattern
?
design-patterns adapter decorator wrapper facade
design-patterns adapter decorator wrapper facade
New contributor
New contributor
edited yesterday
jaco0646
4,36652345
4,36652345
New contributor
asked Nov 15 at 8:34
zack
696
696
New contributor
New contributor
2
My take on it is that a wrapper class is no pattern, it just wraps existing classes. Patterns like Decorator, Facade and Adapter often make use of a wrapper class. But that's only my opinion!
– Nordiii
Nov 15 at 8:43
add a comment |
2
My take on it is that a wrapper class is no pattern, it just wraps existing classes. Patterns like Decorator, Facade and Adapter often make use of a wrapper class. But that's only my opinion!
– Nordiii
Nov 15 at 8:43
2
2
My take on it is that a wrapper class is no pattern, it just wraps existing classes. Patterns like Decorator, Facade and Adapter often make use of a wrapper class. But that's only my opinion!
– Nordiii
Nov 15 at 8:43
My take on it is that a wrapper class is no pattern, it just wraps existing classes. Patterns like Decorator, Facade and Adapter often make use of a wrapper class. But that's only my opinion!
– Nordiii
Nov 15 at 8:43
add a comment |
5 Answers
5
active
oldest
votes
up vote
6
down vote
If you refer to wrapping primitive
Wrapper classes provide a way to use primitive types as objects
Adapter pattern is the most exact meaning:
A decorator makes it possible to add or alter behavior of an interface at run-time. Alternatively, the adapter can be used when the wrapper must respect a particular interface and must support polymorphic behavior, and the Facade when an easier or simpler interface to an underlying object is desired
We use Wrapper class ability to use primitive as Objects, meaning add support to a polymorphic behavior
Might be worthwhile adding examples of wrappers as adapters - eg boxing of primitive types, COM component wrappers.
– just.another.programmer
2 days ago
@just.another.programmer the question already ask about boxing of primitive type,no ?
– user7294900
2 days ago
Your adapter pattern link goes to the decorator pattern
– Michael
2 days ago
@Michael true, but it has good description when to use either
– user7294900
2 days ago
1
I didn't see anything explicit about boxing of primitives in the question. OP just says "Wrapper Classes".
– just.another.programmer
2 days ago
|
show 1 more comment
up vote
5
down vote
All of the three design patterns in someway describe a wrapper:
- Decorator pattern. Wraps a component and potentially decorates it with some additional characteristics.
- Adapter pattern. Simply wraps a component to provide a suitable interface for consumers.
- Facade pattern. Wraps a component to facilitate the usage of otherwise complex external interface.
Not a decorator. A decorator isolates behavior into separate classes which can be added to the "main" component independently. The structure requires wrapping the main component, but that's not the main point.
– just.another.programmer
2 days ago
Not a facade. A facade is all about changing the public API of a class. That's a lot more than just "wrapping" it.
– just.another.programmer
2 days ago
Have you checked wikipedia: en.wikipedia.org/wiki/Decorator_pattern?. A basic test is to look the occurences of the word wrapper. Otherwise you can read the Intent part...If you want to find a black dot in white wall you almost certainly always will, but this time is not the point IMO.
– NiVeR
2 days ago
1
If you notice, I said in someway, it doesn't mean===
. It means to some extent. Your points are wrong in my opinion.
– NiVeR
2 days ago
1
Decorator classes wrap the original type as an implementation detail. The key difference is their purpose: to extend or alter behavior, not the interface. It's kind of like the "all squares are rectangles but not all rectangles are squares".
– just.another.programmer
2 days ago
add a comment |
up vote
3
down vote
Well, the answers seems like to indicate that you can wrap an object for many reasons and as such, many patterns. So I'll try to give a more general answer.
A Wrapper is basically an object whose sole purpose is to provide something without modifying the main object (add fonctionnalities, simplify API, serialisation, ... see other answers), that wrapper is generally tightly coupled to the "main" object. For exemples look others answers.
Another alternative for some usage of the wrapper is inheritance, but not for every case.
As such the wrapper is just a technical way of doing some stuff. It is not a pattern in itself.
add a comment |
up vote
1
down vote
They don't follow any of the design patterns that you have mentioned.
Adapter converts the interface of a class to another interface. Primitives do not implement any interfaces.
Decorator adds behaviour of to a class implementing one interface by wrapping it in another that implements the same interface. Primitives do not implement any interfaces.
A facade's purpose is to mask the complex behaviour of the object that it's wrapping. There is nothing less complex in a programming language than a primitive. The clue's in the name. If anything, the wrapper classes are the opposite of this.
Off the top of my here, here's a few design patterns that they do make use of:
Integer
, Long
and Byte
make use of an object pool of flyweight objects, to avoid creating unnecessary instances.
Boolean
somewhat tries to be a multiton (in that the constructor is deprecated) but in practice it isn't.
all Wrapper classes constructor are deprecated in java 9 as docs.oracle.com/javase/9/docs/api/?java/lang/Integer.html
– user7294900
2 days ago
@user7294900 Sure. What's your point?
– Michael
2 days ago
You wrote the note specific forBoolean
– user7294900
2 days ago
@user7294900 Because that's the only one which is (sort of) a multiton (Boolean.TRUE and Boolean.FALSE).
– Michael
2 days ago
add a comment |
up vote
1
down vote
Wrapper classes use composition. The same composition as in the popular maxim, "Favor composition over inheritance." Composition is not a design pattern; however, most OO design patterns use composition as part of their implementation. This is one reason many people struggle to discriminate among different design patterns: the common use of composition makes them all appear the same to a certain degree.
There are two basic parts in a composition relationship: the composer and the composed. You can think of this generally as a part/whole relationship. It may be one-to-one or one-to-many. A wrapper is the composer, i.e. it is the whole. It may wrap one or more composed parts.
Many different design patterns make use of the general composition relationship for different purposes. Many of those different patterns are referred to collectively as "wrappers". The GoF book calls out at least two such patterns.
ADAPTER Also Known As Wrapper
page 139
DECORATOR Also Known As Wrapper
page 175
In summary, Wrapper is not any single design pattern; rather, it is a category of design patterns. Incidentally, we see the same dynamic with the term Factory. There is no single design pattern named Factory; rather, it is a category of design patterns.
add a comment |
5 Answers
5
active
oldest
votes
5 Answers
5
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
6
down vote
If you refer to wrapping primitive
Wrapper classes provide a way to use primitive types as objects
Adapter pattern is the most exact meaning:
A decorator makes it possible to add or alter behavior of an interface at run-time. Alternatively, the adapter can be used when the wrapper must respect a particular interface and must support polymorphic behavior, and the Facade when an easier or simpler interface to an underlying object is desired
We use Wrapper class ability to use primitive as Objects, meaning add support to a polymorphic behavior
Might be worthwhile adding examples of wrappers as adapters - eg boxing of primitive types, COM component wrappers.
– just.another.programmer
2 days ago
@just.another.programmer the question already ask about boxing of primitive type,no ?
– user7294900
2 days ago
Your adapter pattern link goes to the decorator pattern
– Michael
2 days ago
@Michael true, but it has good description when to use either
– user7294900
2 days ago
1
I didn't see anything explicit about boxing of primitives in the question. OP just says "Wrapper Classes".
– just.another.programmer
2 days ago
|
show 1 more comment
up vote
6
down vote
If you refer to wrapping primitive
Wrapper classes provide a way to use primitive types as objects
Adapter pattern is the most exact meaning:
A decorator makes it possible to add or alter behavior of an interface at run-time. Alternatively, the adapter can be used when the wrapper must respect a particular interface and must support polymorphic behavior, and the Facade when an easier or simpler interface to an underlying object is desired
We use Wrapper class ability to use primitive as Objects, meaning add support to a polymorphic behavior
Might be worthwhile adding examples of wrappers as adapters - eg boxing of primitive types, COM component wrappers.
– just.another.programmer
2 days ago
@just.another.programmer the question already ask about boxing of primitive type,no ?
– user7294900
2 days ago
Your adapter pattern link goes to the decorator pattern
– Michael
2 days ago
@Michael true, but it has good description when to use either
– user7294900
2 days ago
1
I didn't see anything explicit about boxing of primitives in the question. OP just says "Wrapper Classes".
– just.another.programmer
2 days ago
|
show 1 more comment
up vote
6
down vote
up vote
6
down vote
If you refer to wrapping primitive
Wrapper classes provide a way to use primitive types as objects
Adapter pattern is the most exact meaning:
A decorator makes it possible to add or alter behavior of an interface at run-time. Alternatively, the adapter can be used when the wrapper must respect a particular interface and must support polymorphic behavior, and the Facade when an easier or simpler interface to an underlying object is desired
We use Wrapper class ability to use primitive as Objects, meaning add support to a polymorphic behavior
If you refer to wrapping primitive
Wrapper classes provide a way to use primitive types as objects
Adapter pattern is the most exact meaning:
A decorator makes it possible to add or alter behavior of an interface at run-time. Alternatively, the adapter can be used when the wrapper must respect a particular interface and must support polymorphic behavior, and the Facade when an easier or simpler interface to an underlying object is desired
We use Wrapper class ability to use primitive as Objects, meaning add support to a polymorphic behavior
edited 2 days ago
answered Nov 15 at 8:38
user7294900
17.8k93056
17.8k93056
Might be worthwhile adding examples of wrappers as adapters - eg boxing of primitive types, COM component wrappers.
– just.another.programmer
2 days ago
@just.another.programmer the question already ask about boxing of primitive type,no ?
– user7294900
2 days ago
Your adapter pattern link goes to the decorator pattern
– Michael
2 days ago
@Michael true, but it has good description when to use either
– user7294900
2 days ago
1
I didn't see anything explicit about boxing of primitives in the question. OP just says "Wrapper Classes".
– just.another.programmer
2 days ago
|
show 1 more comment
Might be worthwhile adding examples of wrappers as adapters - eg boxing of primitive types, COM component wrappers.
– just.another.programmer
2 days ago
@just.another.programmer the question already ask about boxing of primitive type,no ?
– user7294900
2 days ago
Your adapter pattern link goes to the decorator pattern
– Michael
2 days ago
@Michael true, but it has good description when to use either
– user7294900
2 days ago
1
I didn't see anything explicit about boxing of primitives in the question. OP just says "Wrapper Classes".
– just.another.programmer
2 days ago
Might be worthwhile adding examples of wrappers as adapters - eg boxing of primitive types, COM component wrappers.
– just.another.programmer
2 days ago
Might be worthwhile adding examples of wrappers as adapters - eg boxing of primitive types, COM component wrappers.
– just.another.programmer
2 days ago
@just.another.programmer the question already ask about boxing of primitive type,no ?
– user7294900
2 days ago
@just.another.programmer the question already ask about boxing of primitive type,no ?
– user7294900
2 days ago
Your adapter pattern link goes to the decorator pattern
– Michael
2 days ago
Your adapter pattern link goes to the decorator pattern
– Michael
2 days ago
@Michael true, but it has good description when to use either
– user7294900
2 days ago
@Michael true, but it has good description when to use either
– user7294900
2 days ago
1
1
I didn't see anything explicit about boxing of primitives in the question. OP just says "Wrapper Classes".
– just.another.programmer
2 days ago
I didn't see anything explicit about boxing of primitives in the question. OP just says "Wrapper Classes".
– just.another.programmer
2 days ago
|
show 1 more comment
up vote
5
down vote
All of the three design patterns in someway describe a wrapper:
- Decorator pattern. Wraps a component and potentially decorates it with some additional characteristics.
- Adapter pattern. Simply wraps a component to provide a suitable interface for consumers.
- Facade pattern. Wraps a component to facilitate the usage of otherwise complex external interface.
Not a decorator. A decorator isolates behavior into separate classes which can be added to the "main" component independently. The structure requires wrapping the main component, but that's not the main point.
– just.another.programmer
2 days ago
Not a facade. A facade is all about changing the public API of a class. That's a lot more than just "wrapping" it.
– just.another.programmer
2 days ago
Have you checked wikipedia: en.wikipedia.org/wiki/Decorator_pattern?. A basic test is to look the occurences of the word wrapper. Otherwise you can read the Intent part...If you want to find a black dot in white wall you almost certainly always will, but this time is not the point IMO.
– NiVeR
2 days ago
1
If you notice, I said in someway, it doesn't mean===
. It means to some extent. Your points are wrong in my opinion.
– NiVeR
2 days ago
1
Decorator classes wrap the original type as an implementation detail. The key difference is their purpose: to extend or alter behavior, not the interface. It's kind of like the "all squares are rectangles but not all rectangles are squares".
– just.another.programmer
2 days ago
add a comment |
up vote
5
down vote
All of the three design patterns in someway describe a wrapper:
- Decorator pattern. Wraps a component and potentially decorates it with some additional characteristics.
- Adapter pattern. Simply wraps a component to provide a suitable interface for consumers.
- Facade pattern. Wraps a component to facilitate the usage of otherwise complex external interface.
Not a decorator. A decorator isolates behavior into separate classes which can be added to the "main" component independently. The structure requires wrapping the main component, but that's not the main point.
– just.another.programmer
2 days ago
Not a facade. A facade is all about changing the public API of a class. That's a lot more than just "wrapping" it.
– just.another.programmer
2 days ago
Have you checked wikipedia: en.wikipedia.org/wiki/Decorator_pattern?. A basic test is to look the occurences of the word wrapper. Otherwise you can read the Intent part...If you want to find a black dot in white wall you almost certainly always will, but this time is not the point IMO.
– NiVeR
2 days ago
1
If you notice, I said in someway, it doesn't mean===
. It means to some extent. Your points are wrong in my opinion.
– NiVeR
2 days ago
1
Decorator classes wrap the original type as an implementation detail. The key difference is their purpose: to extend or alter behavior, not the interface. It's kind of like the "all squares are rectangles but not all rectangles are squares".
– just.another.programmer
2 days ago
add a comment |
up vote
5
down vote
up vote
5
down vote
All of the three design patterns in someway describe a wrapper:
- Decorator pattern. Wraps a component and potentially decorates it with some additional characteristics.
- Adapter pattern. Simply wraps a component to provide a suitable interface for consumers.
- Facade pattern. Wraps a component to facilitate the usage of otherwise complex external interface.
All of the three design patterns in someway describe a wrapper:
- Decorator pattern. Wraps a component and potentially decorates it with some additional characteristics.
- Adapter pattern. Simply wraps a component to provide a suitable interface for consumers.
- Facade pattern. Wraps a component to facilitate the usage of otherwise complex external interface.
edited 2 days ago
answered Nov 15 at 8:41
NiVeR
6,47141930
6,47141930
Not a decorator. A decorator isolates behavior into separate classes which can be added to the "main" component independently. The structure requires wrapping the main component, but that's not the main point.
– just.another.programmer
2 days ago
Not a facade. A facade is all about changing the public API of a class. That's a lot more than just "wrapping" it.
– just.another.programmer
2 days ago
Have you checked wikipedia: en.wikipedia.org/wiki/Decorator_pattern?. A basic test is to look the occurences of the word wrapper. Otherwise you can read the Intent part...If you want to find a black dot in white wall you almost certainly always will, but this time is not the point IMO.
– NiVeR
2 days ago
1
If you notice, I said in someway, it doesn't mean===
. It means to some extent. Your points are wrong in my opinion.
– NiVeR
2 days ago
1
Decorator classes wrap the original type as an implementation detail. The key difference is their purpose: to extend or alter behavior, not the interface. It's kind of like the "all squares are rectangles but not all rectangles are squares".
– just.another.programmer
2 days ago
add a comment |
Not a decorator. A decorator isolates behavior into separate classes which can be added to the "main" component independently. The structure requires wrapping the main component, but that's not the main point.
– just.another.programmer
2 days ago
Not a facade. A facade is all about changing the public API of a class. That's a lot more than just "wrapping" it.
– just.another.programmer
2 days ago
Have you checked wikipedia: en.wikipedia.org/wiki/Decorator_pattern?. A basic test is to look the occurences of the word wrapper. Otherwise you can read the Intent part...If you want to find a black dot in white wall you almost certainly always will, but this time is not the point IMO.
– NiVeR
2 days ago
1
If you notice, I said in someway, it doesn't mean===
. It means to some extent. Your points are wrong in my opinion.
– NiVeR
2 days ago
1
Decorator classes wrap the original type as an implementation detail. The key difference is their purpose: to extend or alter behavior, not the interface. It's kind of like the "all squares are rectangles but not all rectangles are squares".
– just.another.programmer
2 days ago
Not a decorator. A decorator isolates behavior into separate classes which can be added to the "main" component independently. The structure requires wrapping the main component, but that's not the main point.
– just.another.programmer
2 days ago
Not a decorator. A decorator isolates behavior into separate classes which can be added to the "main" component independently. The structure requires wrapping the main component, but that's not the main point.
– just.another.programmer
2 days ago
Not a facade. A facade is all about changing the public API of a class. That's a lot more than just "wrapping" it.
– just.another.programmer
2 days ago
Not a facade. A facade is all about changing the public API of a class. That's a lot more than just "wrapping" it.
– just.another.programmer
2 days ago
Have you checked wikipedia: en.wikipedia.org/wiki/Decorator_pattern?. A basic test is to look the occurences of the word wrapper. Otherwise you can read the Intent part...If you want to find a black dot in white wall you almost certainly always will, but this time is not the point IMO.
– NiVeR
2 days ago
Have you checked wikipedia: en.wikipedia.org/wiki/Decorator_pattern?. A basic test is to look the occurences of the word wrapper. Otherwise you can read the Intent part...If you want to find a black dot in white wall you almost certainly always will, but this time is not the point IMO.
– NiVeR
2 days ago
1
1
If you notice, I said in someway, it doesn't mean
===
. It means to some extent. Your points are wrong in my opinion.– NiVeR
2 days ago
If you notice, I said in someway, it doesn't mean
===
. It means to some extent. Your points are wrong in my opinion.– NiVeR
2 days ago
1
1
Decorator classes wrap the original type as an implementation detail. The key difference is their purpose: to extend or alter behavior, not the interface. It's kind of like the "all squares are rectangles but not all rectangles are squares".
– just.another.programmer
2 days ago
Decorator classes wrap the original type as an implementation detail. The key difference is their purpose: to extend or alter behavior, not the interface. It's kind of like the "all squares are rectangles but not all rectangles are squares".
– just.another.programmer
2 days ago
add a comment |
up vote
3
down vote
Well, the answers seems like to indicate that you can wrap an object for many reasons and as such, many patterns. So I'll try to give a more general answer.
A Wrapper is basically an object whose sole purpose is to provide something without modifying the main object (add fonctionnalities, simplify API, serialisation, ... see other answers), that wrapper is generally tightly coupled to the "main" object. For exemples look others answers.
Another alternative for some usage of the wrapper is inheritance, but not for every case.
As such the wrapper is just a technical way of doing some stuff. It is not a pattern in itself.
add a comment |
up vote
3
down vote
Well, the answers seems like to indicate that you can wrap an object for many reasons and as such, many patterns. So I'll try to give a more general answer.
A Wrapper is basically an object whose sole purpose is to provide something without modifying the main object (add fonctionnalities, simplify API, serialisation, ... see other answers), that wrapper is generally tightly coupled to the "main" object. For exemples look others answers.
Another alternative for some usage of the wrapper is inheritance, but not for every case.
As such the wrapper is just a technical way of doing some stuff. It is not a pattern in itself.
add a comment |
up vote
3
down vote
up vote
3
down vote
Well, the answers seems like to indicate that you can wrap an object for many reasons and as such, many patterns. So I'll try to give a more general answer.
A Wrapper is basically an object whose sole purpose is to provide something without modifying the main object (add fonctionnalities, simplify API, serialisation, ... see other answers), that wrapper is generally tightly coupled to the "main" object. For exemples look others answers.
Another alternative for some usage of the wrapper is inheritance, but not for every case.
As such the wrapper is just a technical way of doing some stuff. It is not a pattern in itself.
Well, the answers seems like to indicate that you can wrap an object for many reasons and as such, many patterns. So I'll try to give a more general answer.
A Wrapper is basically an object whose sole purpose is to provide something without modifying the main object (add fonctionnalities, simplify API, serialisation, ... see other answers), that wrapper is generally tightly coupled to the "main" object. For exemples look others answers.
Another alternative for some usage of the wrapper is inheritance, but not for every case.
As such the wrapper is just a technical way of doing some stuff. It is not a pattern in itself.
answered 2 days ago
Walfrat
5,0691131
5,0691131
add a comment |
add a comment |
up vote
1
down vote
They don't follow any of the design patterns that you have mentioned.
Adapter converts the interface of a class to another interface. Primitives do not implement any interfaces.
Decorator adds behaviour of to a class implementing one interface by wrapping it in another that implements the same interface. Primitives do not implement any interfaces.
A facade's purpose is to mask the complex behaviour of the object that it's wrapping. There is nothing less complex in a programming language than a primitive. The clue's in the name. If anything, the wrapper classes are the opposite of this.
Off the top of my here, here's a few design patterns that they do make use of:
Integer
, Long
and Byte
make use of an object pool of flyweight objects, to avoid creating unnecessary instances.
Boolean
somewhat tries to be a multiton (in that the constructor is deprecated) but in practice it isn't.
all Wrapper classes constructor are deprecated in java 9 as docs.oracle.com/javase/9/docs/api/?java/lang/Integer.html
– user7294900
2 days ago
@user7294900 Sure. What's your point?
– Michael
2 days ago
You wrote the note specific forBoolean
– user7294900
2 days ago
@user7294900 Because that's the only one which is (sort of) a multiton (Boolean.TRUE and Boolean.FALSE).
– Michael
2 days ago
add a comment |
up vote
1
down vote
They don't follow any of the design patterns that you have mentioned.
Adapter converts the interface of a class to another interface. Primitives do not implement any interfaces.
Decorator adds behaviour of to a class implementing one interface by wrapping it in another that implements the same interface. Primitives do not implement any interfaces.
A facade's purpose is to mask the complex behaviour of the object that it's wrapping. There is nothing less complex in a programming language than a primitive. The clue's in the name. If anything, the wrapper classes are the opposite of this.
Off the top of my here, here's a few design patterns that they do make use of:
Integer
, Long
and Byte
make use of an object pool of flyweight objects, to avoid creating unnecessary instances.
Boolean
somewhat tries to be a multiton (in that the constructor is deprecated) but in practice it isn't.
all Wrapper classes constructor are deprecated in java 9 as docs.oracle.com/javase/9/docs/api/?java/lang/Integer.html
– user7294900
2 days ago
@user7294900 Sure. What's your point?
– Michael
2 days ago
You wrote the note specific forBoolean
– user7294900
2 days ago
@user7294900 Because that's the only one which is (sort of) a multiton (Boolean.TRUE and Boolean.FALSE).
– Michael
2 days ago
add a comment |
up vote
1
down vote
up vote
1
down vote
They don't follow any of the design patterns that you have mentioned.
Adapter converts the interface of a class to another interface. Primitives do not implement any interfaces.
Decorator adds behaviour of to a class implementing one interface by wrapping it in another that implements the same interface. Primitives do not implement any interfaces.
A facade's purpose is to mask the complex behaviour of the object that it's wrapping. There is nothing less complex in a programming language than a primitive. The clue's in the name. If anything, the wrapper classes are the opposite of this.
Off the top of my here, here's a few design patterns that they do make use of:
Integer
, Long
and Byte
make use of an object pool of flyweight objects, to avoid creating unnecessary instances.
Boolean
somewhat tries to be a multiton (in that the constructor is deprecated) but in practice it isn't.
They don't follow any of the design patterns that you have mentioned.
Adapter converts the interface of a class to another interface. Primitives do not implement any interfaces.
Decorator adds behaviour of to a class implementing one interface by wrapping it in another that implements the same interface. Primitives do not implement any interfaces.
A facade's purpose is to mask the complex behaviour of the object that it's wrapping. There is nothing less complex in a programming language than a primitive. The clue's in the name. If anything, the wrapper classes are the opposite of this.
Off the top of my here, here's a few design patterns that they do make use of:
Integer
, Long
and Byte
make use of an object pool of flyweight objects, to avoid creating unnecessary instances.
Boolean
somewhat tries to be a multiton (in that the constructor is deprecated) but in practice it isn't.
answered 2 days ago
Michael
17.7k73167
17.7k73167
all Wrapper classes constructor are deprecated in java 9 as docs.oracle.com/javase/9/docs/api/?java/lang/Integer.html
– user7294900
2 days ago
@user7294900 Sure. What's your point?
– Michael
2 days ago
You wrote the note specific forBoolean
– user7294900
2 days ago
@user7294900 Because that's the only one which is (sort of) a multiton (Boolean.TRUE and Boolean.FALSE).
– Michael
2 days ago
add a comment |
all Wrapper classes constructor are deprecated in java 9 as docs.oracle.com/javase/9/docs/api/?java/lang/Integer.html
– user7294900
2 days ago
@user7294900 Sure. What's your point?
– Michael
2 days ago
You wrote the note specific forBoolean
– user7294900
2 days ago
@user7294900 Because that's the only one which is (sort of) a multiton (Boolean.TRUE and Boolean.FALSE).
– Michael
2 days ago
all Wrapper classes constructor are deprecated in java 9 as docs.oracle.com/javase/9/docs/api/?java/lang/Integer.html
– user7294900
2 days ago
all Wrapper classes constructor are deprecated in java 9 as docs.oracle.com/javase/9/docs/api/?java/lang/Integer.html
– user7294900
2 days ago
@user7294900 Sure. What's your point?
– Michael
2 days ago
@user7294900 Sure. What's your point?
– Michael
2 days ago
You wrote the note specific for
Boolean
– user7294900
2 days ago
You wrote the note specific for
Boolean
– user7294900
2 days ago
@user7294900 Because that's the only one which is (sort of) a multiton (Boolean.TRUE and Boolean.FALSE).
– Michael
2 days ago
@user7294900 Because that's the only one which is (sort of) a multiton (Boolean.TRUE and Boolean.FALSE).
– Michael
2 days ago
add a comment |
up vote
1
down vote
Wrapper classes use composition. The same composition as in the popular maxim, "Favor composition over inheritance." Composition is not a design pattern; however, most OO design patterns use composition as part of their implementation. This is one reason many people struggle to discriminate among different design patterns: the common use of composition makes them all appear the same to a certain degree.
There are two basic parts in a composition relationship: the composer and the composed. You can think of this generally as a part/whole relationship. It may be one-to-one or one-to-many. A wrapper is the composer, i.e. it is the whole. It may wrap one or more composed parts.
Many different design patterns make use of the general composition relationship for different purposes. Many of those different patterns are referred to collectively as "wrappers". The GoF book calls out at least two such patterns.
ADAPTER Also Known As Wrapper
page 139
DECORATOR Also Known As Wrapper
page 175
In summary, Wrapper is not any single design pattern; rather, it is a category of design patterns. Incidentally, we see the same dynamic with the term Factory. There is no single design pattern named Factory; rather, it is a category of design patterns.
add a comment |
up vote
1
down vote
Wrapper classes use composition. The same composition as in the popular maxim, "Favor composition over inheritance." Composition is not a design pattern; however, most OO design patterns use composition as part of their implementation. This is one reason many people struggle to discriminate among different design patterns: the common use of composition makes them all appear the same to a certain degree.
There are two basic parts in a composition relationship: the composer and the composed. You can think of this generally as a part/whole relationship. It may be one-to-one or one-to-many. A wrapper is the composer, i.e. it is the whole. It may wrap one or more composed parts.
Many different design patterns make use of the general composition relationship for different purposes. Many of those different patterns are referred to collectively as "wrappers". The GoF book calls out at least two such patterns.
ADAPTER Also Known As Wrapper
page 139
DECORATOR Also Known As Wrapper
page 175
In summary, Wrapper is not any single design pattern; rather, it is a category of design patterns. Incidentally, we see the same dynamic with the term Factory. There is no single design pattern named Factory; rather, it is a category of design patterns.
add a comment |
up vote
1
down vote
up vote
1
down vote
Wrapper classes use composition. The same composition as in the popular maxim, "Favor composition over inheritance." Composition is not a design pattern; however, most OO design patterns use composition as part of their implementation. This is one reason many people struggle to discriminate among different design patterns: the common use of composition makes them all appear the same to a certain degree.
There are two basic parts in a composition relationship: the composer and the composed. You can think of this generally as a part/whole relationship. It may be one-to-one or one-to-many. A wrapper is the composer, i.e. it is the whole. It may wrap one or more composed parts.
Many different design patterns make use of the general composition relationship for different purposes. Many of those different patterns are referred to collectively as "wrappers". The GoF book calls out at least two such patterns.
ADAPTER Also Known As Wrapper
page 139
DECORATOR Also Known As Wrapper
page 175
In summary, Wrapper is not any single design pattern; rather, it is a category of design patterns. Incidentally, we see the same dynamic with the term Factory. There is no single design pattern named Factory; rather, it is a category of design patterns.
Wrapper classes use composition. The same composition as in the popular maxim, "Favor composition over inheritance." Composition is not a design pattern; however, most OO design patterns use composition as part of their implementation. This is one reason many people struggle to discriminate among different design patterns: the common use of composition makes them all appear the same to a certain degree.
There are two basic parts in a composition relationship: the composer and the composed. You can think of this generally as a part/whole relationship. It may be one-to-one or one-to-many. A wrapper is the composer, i.e. it is the whole. It may wrap one or more composed parts.
Many different design patterns make use of the general composition relationship for different purposes. Many of those different patterns are referred to collectively as "wrappers". The GoF book calls out at least two such patterns.
ADAPTER Also Known As Wrapper
page 139
DECORATOR Also Known As Wrapper
page 175
In summary, Wrapper is not any single design pattern; rather, it is a category of design patterns. Incidentally, we see the same dynamic with the term Factory. There is no single design pattern named Factory; rather, it is a category of design patterns.
answered yesterday
jaco0646
4,36652345
4,36652345
add a comment |
add a comment |
zack is a new contributor. Be nice, and check out our Code of Conduct.
zack is a new contributor. Be nice, and check out our Code of Conduct.
zack is a new contributor. Be nice, and check out our Code of Conduct.
zack is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53315266%2fwhat-is-the-design-pattern-that-wrapper-classes-use-in-java%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
2
My take on it is that a wrapper class is no pattern, it just wraps existing classes. Patterns like Decorator, Facade and Adapter often make use of a wrapper class. But that's only my opinion!
– Nordiii
Nov 15 at 8:43