Scraping Craigslist Listings with Kotlin

This article explains how to scrape Craigslist apartment listings using Kotlin and the Ktor client library. We'll go through each part of the code.

First add Ktor to build.gradle.kts:

implementation("io.ktor:ktor-client-core:1.5.2")
implementation("io.ktor:ktor-client-cio:1.5.2")

Import the Ktor client:

import io.ktor.client.*

Ktor provides a HttpClient for HTTP requests.

Set the URL to scrape:

val url = "<https://sfbay.craigslist.org/search/apa>"

Make the HTTP request and get the response text:

val client = HttpClient()
val response = client.get<String>(url)
val html = response.body()

Parse the HTML using kotlinx.html:

val doc = HtmlParser.parse(html)

If you check the source code of Craigslist listings you can see that the listings area code looks something like this…

You can see the code block that generates the listing…

<li class="cl-static-search-result" title="Situated in Sunnyvale!, Recycling Center, 1/BD">
            <a href="https://sfbay.craigslist.org/sby/apa/d/santa-clara-situated-in-sunnyvale/7666802370.html">
                <div class="title">Situated in Sunnyvale!, Recycling Center, 1/BD</div>

                <div class="details">
                    <div class="price">$2,150</div>
                    <div class="location">
                        sunnyvale
                    </div>
                </div>
            </a>
        </li>

its encapsulated in the cl-static-search-result class. We also need to get the title class div and the price and location class divs to get all the data

Find all listing nodes with select:

val listings = doc.select("li.cl-static-search-result")

Loop through listings and extract info:

for (listing in listings) {

  val title = listing.select(".title").text()
  val price = listing.select(".price").text()
  val location = listing.select(".location").text()

  val link = listing.select("a").attr("href")

  println("$title $price $location $link")

}

The full Kotlin code:

import io.ktor.client.*
import kotlinx.html.*

val url = "<https://sfbay.craigslist.org/search/apa>"

val client = HttpClient()
val response = client.get<String>(url)
val html = response.body()

val doc = HtmlParser.parse(html)

val listings = doc.select("li.cl-static-search-result")

for (listing in listings) {

  val title = listing.select(".title").text()
  val price = listing.select(".price").text()
  val location = listing.select(".location").text()

  val link = listing.select("a").attr("href")

  println("$title $price $location $link")

}

This walks through scraping Craigslist listings in Kotlin.

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