Книги
Kotlin
Розділ 11. HTML та веб
Завантаження веб-сторінки

Kotlin:
Завантаження веб-сторінки

Як це зробити:

We use HttpURLConnection to fetch web content in Kotlin. Here’s the bare-bones way to do it:

import java.net.HttpURLConnection
import java.net.URL

fun downloadWebPage(url: String): String {
    val connection = URL(url).openConnection() as HttpURLConnection
    return try {
        connection.inputStream.bufferedReader().use { it.readText() }
    } finally {
        connection.disconnect()
    }
}

fun main() {
    val webContent = downloadWebPage("http://example.com")
    println(webContent.substring(0, 100)) // print first 100 chars
}

Sample output:

<!doctype html>
<html>
<head>
    <title>Example Domain</title>
...

Поглиблений Розбір:

Back in the day, fetching a web page meant lots of manual work with sockets. Libraries like Apache’s HttpClient simplified it, and Kotlin’s extension functions make the syntax even cleaner.

Nowadays, HttpURLConnection is the raw way to handle HTTP in Java/Kotlin but not the only one. OkHttp and Retrofit are modern alternatives offering more features and simpler, more readable code.

Details matter. While HttpURLConnection auto-handles redirects, handling errors and timeouts needs extra code. Be mindful of UTF-8 and content parsing. Tools like Jsoup can save your day when working with HTML.

Lastly, keep in mind networking tasks should run on background threads to keep UIs responsive.

Також Гляньте:

Happy coding, and remember to check the rules regarding web scraping and the legality in your context!

Аналіз HTML