By Alvin Alexander. Last updated: January 28, 2018
| The Bill Gates Bestseller | |
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How to Avoid a Climate Disaster |
In case you ever need to read an Atom or RSS feed using Scala, this example code shows how to use the Java ROME library in your Scala code:
import java.net.URL
import com.rometools.rome.feed.synd.{SyndFeed}
import com.rometools.rome.io.SyndFeedInput
import com.rometools.rome.io.XmlReader
import scala.collection.JavaConverters._
object AtomAndRssReader extends App {
// NOTE: code can throw exceptions
val feedUrl = new URL("https://www.npr.org/rss/rss.php?id=100")
val input = new SyndFeedInput
val feed: SyndFeed = input.build(new XmlReader(feedUrl))
//println(feed)
// `feed.getEntries` has type `java.util.List[SyndEntry]`
val entries = asScalaBuffer(feed.getEntries).toVector
for (entry <- entries) {
println("Title: " + entry.getTitle)
println("URI: " + entry.getUri)
println("Date: " + entry.getUpdatedDate)
// java.util.List[SyndLink]
val links = asScalaBuffer(entry.getLinks).toVector
for (link <- links) {
println("Link: " + link.getHref)
}
val contents = asScalaBuffer(entry.getContents).toVector
for (content <- contents) {
println("Content: " + content.getValue)
}
val categories = asScalaBuffer(entry.getCategories).toVector
for (category <- categories) {
println("Category: " + category.getName)
}
println("")
}
}
A few notes:
- The code uses Scala’s JavaConverters class to convert the java.util.List instances into something more usable
- You need to add the Rome dependency to your build.sbt file (
"com.rometools" % "rome" % "1.8.1") - Of course the ROME library does all the heavy lifting; I just show how to use it in Scala, in particular with the JavaConverters class
The output
Here’s an abridged version of what the output from this code looks like today:
Title: Episode 820: P Is For Phosphorus
URI: https://www.npr.org/sections/money/2018/01/26/581156723/episode-820-p-is-for-phosphorus?utm_medium=RSS&utm_campaign=storiesfromnpr
Date: null
Content: <img src='https://media.npr.org/assets/img/2018/01/26/gettyimages-168997967_wide-3e6007bd49a94a161553cba256335550e12cfb37.jpg?s=600' /><p>Phosphate is a crucial element, for farming, and for life ...
Title: The 10 Events You Need To Know To Understand The Almost-Firing Of Robert Mueller
URI: https://www.npr.org/2018/01/26/580964814/the-10-events-you-need-to-know-to-understand-the-almost-firing-of-robert-mueller?utm_medium=RSS&utm_campaign=storiesfromnpr
Date: null
Content: <img src='https://media.npr.org/assets/img/2018/01/26/mueller-2013_wide-ea9e74cdb89431d2e2ebd476acc67cce3cd67167.jpg?s=600' /><p>Everything about this story revolves around obstruction of justice ...
Note that the Date output is null. I haven’t looked into that yet — it’s not important for my needs — but as you can see, the rest of the output looks just fine, and the code works as intended.
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