我们何时以及为什么需要将一个班级分为多个班级？

Question

I am an android beginner developer. Currently, I am developing an application. However, my class is quite large because there are many UI components (to handle onClick, onProgressBarChanged, etc.). Most of my components are dynamic. So, I have method to create those components.

Now I split some methods for initializing UI components into another class. At this point, I am trying to think/search for a good reason to split my class into several classes.

Advantage: maintainability, testability, reusability

Disadvantage: reduce runtime performance

I am not sure that there is any advantage or disadvantage that I have missed?

Furthermore, I will divide a class when I find an overlap method I am not sure that there is another situation when a class must be divided.

Answer 1

First, if you've never looked into refactoring , then I would strongly encourage you to do so. Martin Fowler has some excellent resources to get you started. But, I'm getting slightly ahead of myself.

To begin with, you split out classes to maintain a clear delineation of responsibilities. You can think of the SOLID principle here - each class does one thing, and one thing very clearly.

If you notice that a method , let alone a class , is doing more than one thing, then that is a good time to stop and refactor - that is, take the code you have, and apply a particular, focused refactoring to it to improve readability and flow, while maintaining the same functionality. You're essentially looking for code smells - parts of the code that are suspect, not following a specific contract or methodology, or are legitimate anti-patterns - which are, themselves, practices that developers strive to avoid .

Programs that deal with UI (especially in Java) tend to be pretty verbose. What you should avoid doing is placing any conditional business logic in the UI layer, for ease of separability, testing and clarity. Make use of the Model-View-Controller pattern to understand and abstract away the necessary separations between the UI (Views), and the actual work that's needed to be done (Controllers), while maintaining some semblance of state (Models).

Answer 2

We use OOPs Concept in Android(core java) Application Development. If we split our one class in many class it gives a good sense of maintainability, re-usability, Security and Easy change in Coding during Development. As for example:- Util class for Database handling, Network Class for Internet connection , Dialog class for different type dialog and so... This way we can categories our coding and change or re use it any time. So it is good practice to follow the OOPS concept during Development.

Thanks