Conditional class declaration

[bitter tulip]

Hey, I'd like to define a class depending on a boolean

Theres two implementation of the same object "Object", implementation A and implementation B.

If boolean is true, Object is defined as implementation A, otherwise it is defined as implementation B
Example of a working python code

class Hello:
    def __init__(self):
        self.greeting = "Hello!"
class Salut:
    def __init__(self):
        self.greeting = "Salut!"
if my_switch:
    Hello = Salut

# Pseudo code equivalent:
if my_switch:
    class Hello:
        def __init__(self):
            self.greeting = "Hello!"
else:
    class Hello:
        def __init__(self):
            self.greeting = "Salut!"

In java, implementation A is public class RegionFile extends Thread, B is public class RegionFile implements AutoCloseable, and the implementation is very different.
I cannot change the code of the project according to this single declaration, so i'd like to change this class according to a boolean.
How can i do that ?

[mortal glade]

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[bitter tulip]

Conditional class declaration

[stone shadow]

That reminds me of the factory pattern, but not sure I understand what you want to do

[bitter tulip]

I've got a whole project using RegionFile default implementation (which is A).
We've come with a newer implementation of this RegionFile object (B implementation). (which is faster and very different)
We'd like to allow users to choose the implementation they want (boolean).
If that boolean if true, the implementation is A, otherwise its B.

Pseudocode:

legacy_implementation = get_user_config_file() # The user want to use the old implementation ?
if legacy_implementation:
    class RegionFile:
        #... Here come the legacy RegionFile code
else:
    class RegionFile:
        #... Here come the new RegionFile code

[stone shadow]

Can you create an Interface that both implementations A and B implement?

Or do they already implement an interface?

[bitter tulip]

One already implement an interface, the other extends an object

[stone shadow]

I think if they both implement the same interface you can easily use the factory pattern https://www.tutorialspoint.com/design_pattern/factory_pattern.htm

[bitter tulip]

I've read about factory pattern with your first comment, do you think this will work ?
Or should i "tryandsee" ?

class LegacyRegionFile implements RegionFile, AutoCloseable{
    // Legacy implementation code
}

class NewRegionFile extends Thread implements RegionFile {
    // New implementation code
}

class RegionFileFactory {
    public static RegionFile getRegionFile(boolean useLegacy) {
        if (useLegacy) {
            return new LegacyRegionFile();
        } else {
            return new NewRegionFile();
        }
    }
}

I don't know if i should change other parts of the project, I'd like to keep it the same

Meaning that my code don't use getRegionFile at all, so i should recode some parts of it

[stone shadow]

I guess i would try, it looks good so far imho. Maybe you also need to implement AutoCloseable in NewRegionFile?