What built-in tools and libraries for working with network protocols and connections do you know and have used?

In Android, the following built-in tools and libraries are often used for working with network protocols and connections:

• HttpURLConnection — the standard Java class for performing HTTP requests, suitable for simple cases.

• OkHttp — a popular third-party library for HTTP client with support for asynchronous requests, caching, and WebSocket.

• Retrofit — a library from Square built on top of OkHttp, simplifying the creation of REST API clients using annotations.

• Volley — a library from Google for network requests with support for queues and caching.

• WebSocket API — for bidirectional data exchange in real-time.

• Socket and ServerSocket — Java classes for working with TCP connections at a low level.

Example of using OkHttp for a GET request:

val client = OkHttpClient()
val request = Request.Builder()
    .url("https://api.example.com/data")
    .build()

client.newCall(request).enqueue(object : Callback {
    override fun onFailure(call: Call, e: IOException) {
        // handle error
    }

    override fun onResponse(call: Call, response: Response) {
        val body = response.body?.string()
        // handle response
    }
})

These tools allow effective network operations in Android applications.