[>] Create domain model (records)

Author: nipafx

README.md

@@ -1,3 +1,14 @@
 # Modern Java in Action
 
 A repository for my live-coding talk [Modern Java in Action](https://nipafx.dev/talk-java-action).
+
+## Next
+
+Records:
+* `record ExternalPage(URI url, String content)`
+	* compact constructor checks all arguments
+	* `equals` with `instanceof`
+* `record GitHubPrPage(URI url, String content, Set<URI> links, int prNumber)`
+	* compact constructor checks all arguments
+	* additional constructor without `links`
+	* `equals` with `instanceof`

src/main/java/dev/nipafx/demo/modern/GitHubCrawl.java

@@ -0,0 +1,29 @@
+package dev.nipafx.demo.modern;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+public class GitHubCrawl {
+
+	/**
+	 * @param args 0: path to GitHub issue or PR page
+	 *             1: depth of tree that will be built
+	 */
+	public static void main(String[] args) throws Exception {
+		var config = Configuration.parse(args);
+
+	}
+
+	private record Configuration(URI seedUrl, int depth) {
+
+		static Configuration parse(String[] args) throws URISyntaxException {
+			if (args.length < 2)
+				throw new IllegalArgumentException("Please specify the seed URL and depth.");
+			var seedUrl = new URI(args[0]);
+			var depth = Integer.parseInt(args[1]);
+			return new Configuration(seedUrl, depth);
+		}
+
+	}
+
+}

src/main/java/module-info.java

@@ -0,0 +1,2 @@
+module gh.crawler {
+}