Design principles for Java classes

1, cohesion

A class should describe a single entity, and all class operations should logically fit together to support a coherent goal. For example: Students and faculty belong to different entities, and two classes should be defined.

2. Consistency

To follow a certain design style and naming habits. Select the name of the information for the class, method, and data field. The popular style is to put the data declaration before the construction method and put the construction method before the method.

It is not a good habit to choose a name that is consistent and to choose a different name for a similar operation.

If you do not want the user to create an object for the class, you can declare a private construction method in the class.

3, encapsulation of

Hides its data field with the private modifier to avoid direct user access. If you want to make the data field readable, you can use the Get method, or you can use the Set method if you want the data field to be updatable.

4. Clarity

Class should have a very clear contract that is easy to interpret and understand.

Methods should be defined intuitively without confusion.

You should not declare a data field from another data domain.

5. Use the class name to refer to static variables and methods.

6. Do not initialize the static data field directly from the constructor by passing parameters. It is best to use static set methods to change the static data field.

7, class modifier private(can only be accessed in this class),default (can only be accessed in the same package), protected(could be accessed by classes and subclasses in the same package), public (classes in different packages can also be accessed). Subclasses can only extend accessibility in the parent class, not the accessibility of the parent class.

8. Final indicates that a class is the ultimate and cannot be a parent class. Similarly, an ultimate method cannot be overridden by its subclasses.

Design principles for Java classes