The definition and function of an adapter is a design pattern that converts the interface of a class into another interface expected by the client, allowing incompatible classes to collaborate seamlessly. Adapters can solve the problem of interface incompatibility in software systems, allowing different classes to work together.
The role of adapters is mainly reflected in the following aspects:
Compatibility: Adapters can adapt old and incompatible interfaces to compatible interfaces, enabling data exchange between different versions of software and devices from different manufacturers, improving system universality. Reusability: Adapters can reuse existing classes to adapt to different environments and improve code reusability. Decoupling: The adapter can decouple the client from the target class, and the client only needs to interact with the adapter without directly interacting with the target class. The principle analysis of adapters is mainly achieved through the packaging of the intermediate layer, which is divided into two forms: class adapters and object adapters.
Class adapter Class adapter implements the functionality of the adapter by inheriting the target class and implementing the interface expected by the client. In the adapter class, by inheriting the target class, methods of the target class can be called; By implementing the interface expected by the client, the methods of the target class can be converted into methods available to the client.
The schematic diagram of the class adapter is as follows:
The 
object adapter implements the functionality of the adapter by holding an instance object of the target class. In the adapter class, by holding the instance object of the target class, methods of the target class can be called; By implementing the interface expected by the client, the methods of the target class can be converted into methods available to the client.
The schematic diagram of the object adapter is as follows:
The main function of the adapter is to solve incompatible interface problems and enable different classes to work together. By packaging the adapter, compatibility, reusability, and decoupling can be achieved. Adapters can be divided into two forms: class adapters and object adapters. Class adapters adapt through inheritance and implementation, while object adapters adapt by holding instance objects of the target class.
