What is the main role of the Retrofit library in interacting with REST API in Android development?

Retrofit is a library for Android that simplifies interaction with REST APIs. It allows you to describe HTTP requests as interfaces in Java or Kotlin, and then automatically generates code to execute these requests and handle responses.

The main roles of Retrofit:

• Abstract the details of network requests.
• Automatically serialize and deserialize JSON or other data formats.
• Provide a convenient and type-safe way to work with APIs.

Example of using Retrofit for a GET request:

interface ApiService {
    @GET("users/{id}")
    suspend fun getUser(@Path("id") userId: String): User
}

val retrofit = Retrofit.Builder()
    .baseUrl("https://api.example.com/")
    .addConverterFactory(GsonConverterFactory.create())
    .build()

val api = retrofit.create(ApiService::class.java)

// In a coroutine
val user = api.getUser("123")

Thus, Retrofit simplifies and structures working with REST APIs in Android applications.