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How to name class which will read and write configuration to file

pavelkastornii

5/26/2015 9:39:00 PM

I have a Configuration class and conf.xml file which contains configuration data. I am thinking about naming class, that will read data from xml-> java and write data java-> xml. ConfigProvider is not good way as it suitable onlt for xml->java. ConfigReaderWriter is a better, but maybe someone will suggest another variants?
6 Answers

August Karlstrom

5/27/2015 2:03:00 PM

0

On 2015-05-26 23:39, pavelkastornii@gmail.com wrote:
> I have a Configuration class and conf.xml file which contains
> configuration data. I am thinking about naming class, that will read
> data from xml-> java and write data java-> xml. ConfigProvider is not
> good way as it suitable onlt for xml->java. ConfigReaderWriter is a
> better, but maybe someone will suggest another variants?
>

Why not simply add the read and write methods to the Configuration class?


-- August

Daniel Pitts

5/28/2015 5:14:00 AM

0

On 5/27/15 7:02 AM, August Karlstrom wrote:
> On 2015-05-26 23:39, pavelkastornii@gmail.com wrote:
>> I have a Configuration class and conf.xml file which contains
>> configuration data. I am thinking about naming class, that will read
>> data from xml-> java and write data java-> xml. ConfigProvider is not
>> good way as it suitable onlt for xml->java. ConfigReaderWriter is a
>> better, but maybe someone will suggest another variants?
>>
>
> Why not simply add the read and write methods to the Configuration class?
That is a terrible idea if this is a long-lived project. What happens
when they want to support yml too? Or json? Or something else. Then
your Configuration class has so many responsibilities that it is a mess...

If you need to write the data to a file, I would have an interface
"ConfigurationWriter" with the "XmlConfigurationWriter" implementation.

I would have a separate interface "ConfigurationReader" with the
"XmlConfigurationReader" implementation.


I would also suggest that the interfaces don't know about a specific
file, but have an argument passed to the load/save method which is the
stream to read from/write to. (For example, InputStream/OutputStream in
Java)

Hope this helps,
Daniel.

August Karlstrom

5/28/2015 6:33:00 AM

0

On 2015-05-28 07:13, Daniel Pitts wrote:
> On 5/27/15 7:02 AM, August Karlstrom wrote:
>> On 2015-05-26 23:39, pavelkastornii@gmail.com wrote:
>>> I have a Configuration class and conf.xml file which contains
>>> configuration data. I am thinking about naming class, that will read
>>> data from xml-> java and write data java-> xml. ConfigProvider is not
>>> good way as it suitable onlt for xml->java. ConfigReaderWriter is a
>>> better, but maybe someone will suggest another variants?
>>>
>>
>> Why not simply add the read and write methods to the Configuration class?
> That is a terrible idea if this is a long-lived project. What happens
> when they want to support yml too? Or json? Or something else.

If you try to anticipate every possible future change to the
requirements your application will indeed be very complex. In this
(unlikely) case I would rather let a separate tool handle the conversion
to XML.

http://www.manageability.org/blog/stuff/over-abstraction-java-achilles...


-- August

Daniel Pitts

5/28/2015 4:23:00 PM

0

On 5/27/15 11:32 PM, August Karlstrom wrote:
> On 2015-05-28 07:13, Daniel Pitts wrote:
>> On 5/27/15 7:02 AM, August Karlstrom wrote:
>>> On 2015-05-26 23:39, pavelkastornii@gmail.com wrote:
>>>> I have a Configuration class and conf.xml file which contains
>>>> configuration data. I am thinking about naming class, that will read
>>>> data from xml-> java and write data java-> xml. ConfigProvider is not
>>>> good way as it suitable onlt for xml->java. ConfigReaderWriter is a
>>>> better, but maybe someone will suggest another variants?
>>>>
>>>
>>> Why not simply add the read and write methods to the Configuration
>>> class?
>> That is a terrible idea if this is a long-lived project. What happens
>> when they want to support yml too? Or json? Or something else.
>
> If you try to anticipate every possible future change to the
> requirements your application will indeed be very complex. In this
> (unlikely) case I would rather let a separate tool handle the conversion
> to XML.
It really depends on the type of product you are creating, including the
expected lifetime and user-base.

However, the "S.O.L.I.D" principles are often helpful regardless of what
your system ultimately aims to be.

In particular, the "Single Responsibility Principle" seems relevant
here. A class that represents a Configuration, shouldn't also represent
a ConfigurationLoader and ConfigurationSaver.

August Karlstrom

5/28/2015 7:26:00 PM

0

On 2015-05-28 18:23, Daniel Pitts wrote:
> In particular, the "Single Responsibility Principle" seems relevant
> here. A class that represents a Configuration, shouldn't also represent
> a ConfigurationLoader and ConfigurationSaver.

To me this makes as much sense as saying that a class that represents a
stack shouldn't also represent a stack pusher and a stack popper. As I
see it the configuration class doesn't *represent* a loader or a saver -
the methods `load' and `save' are just operations on the configuration.


-- August

Daniel Pitts

5/29/2015 4:28:00 AM

0

On 5/28/15 12:25 PM, August Karlstrom wrote:
> On 2015-05-28 18:23, Daniel Pitts wrote:
>> In particular, the "Single Responsibility Principle" seems relevant
>> here. A class that represents a Configuration, shouldn't also represent
>> a ConfigurationLoader and ConfigurationSaver.
>
> To me this makes as much sense as saying that a class that represents a
> stack shouldn't also represent a stack pusher and a stack popper.
The property of "being able to push and pop items" is a defining feature
of a Stack abstraction. Would you call it a Stack if you couldn't push,
or pop? I'm going to assume not.

Now, would you call a Configuration class a Configuration if it couldn't
read itself from a file or write itself out? I'd venture to say you would.

> As I
> see it the configuration class doesn't *represent* a loader or a saver -
> the methods `load' and `save' are just operations on the configuration.

Having the "Loader" and "Saver" operations be handled by distinct
classes helps in several ways. Not the least of which is that it
provides a more flexible design. It also reduces "clutter" in the
Configuration class.

If the loading process is complex enough, you could have a bunch of
private helper methods to go along with the load. Now you've got many
lines of code in the Configuration class that isn't related to "being a
Configuration"