Adapter Pattern Explained Simply

The Adapter pattern is a structural design pattern that allows a class’s interface to be converted into another interface that the client expects. By creating an adapter class, the Adapter pattern converts incompatible interfaces into compatible ones, enabling classes that were originally unable to work together to work together.

The Adapter pattern consists of the following roles:

1. Target interface: It defines the interface that the client expects, and the adapter will implement this interface.
2. Adapter class: Converts incompatible interfaces into the target interface by implementing the target interface.
3. Adaptee: The class or interface that needs to be adapted.
4. Client: A class that operates using the target interface.

The working principle of the Adapter pattern is as follows:

1. The client calls a method from the target interface.
2. The adapter class implements the target interface and calls the corresponding method of the source interface in its methods.
3. The source interface passes method calls to the actual class.
4. The actual class carries out the corresponding operation and returns the result.
5. The adapter class returns the results to the client.

Benefits of the Adapter pattern include:

1. Providing a way to be compatible with different interfaces, avoiding the need to modify existing code.
2. It allows incompatible classes to work together, improving code reusability.
3. Existing classes can be adapted to meet new requirements, increasing the flexibility of the code.

Some drawbacks of the adapter pattern are:

1. Increased the complexity of the code and introduced additional classes.
2. In some cases, extensive adaptation work may be required, leading to complex and difficult-to-maintain code.

Adapter pattern is suitable for the following cases:

1. We need to use an existing class, but its interface is not compatible with the current code.
2. It is necessary to create a reusable class that can work in conjunction with multiple incompatible classes.

In summary, the adapter pattern converts incompatible interfaces into compatible ones by creating an adapter class. This allows classes that were originally unable to work together to now collaborate. The adapter pattern improves code reusability and flexibility but also adds complexity to the code.