added javalin endpoints in main.java

demo/src/main/java/com/example/Main.java

@@ -1,11 +1,53 @@
 package app;
 
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+
 import io.javalin.Javalin;
 
 public class Main {
     public static void main(String[] args) {
         Javalin app = Javalin.create()
+
+            // Endpoint 1: The original root endpoint
             .get("/", ctx -> ctx.result("Hello from Javalin on Hugging Face Spaces!"))
+
+            // Endpoint 2: A dynamic endpoint that takes a name from the path
+            // Example: Accessing /hello/John will display "Hello, John!"
+            .get("/hello/{name}", ctx -> {
+                String name = ctx.pathParam("name"); // Extracts "name" from the URL path
+                ctx.result("Hello, " + name + "!");
+            })
+
+            // Endpoint 3: An endpoint that calls an external API
+            // This endpoint fetches a random fact and returns it.
+            .get("/random-fact", ctx -> {
+                // Use Java's built-in HttpClient to make the API call
+                HttpClient client = HttpClient.newHttpClient();
+                HttpRequest request = HttpRequest.newBuilder()
+                        .uri(URI.create("https://uselessfacts.jsph.pl/api/v2/facts/random?language=en"))
+                        .build();
+
+                try {
+                    // Send the request and get the response
+                    // We ask for the response body as a String
+                    HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+                    // Set the response header to indicate the content is JSON
+                    ctx.header("Content-Type", "application/json");
+                    // Return the body from the external API call
+                    ctx.result(response.body());
+
+                } catch (Exception e) {
+                    // If the API call fails, return a server error status and message
+                    ctx.status(500);
+                    ctx.result("{\"error\": \"Failed to fetch a random fact.\"}");
+                }
+            })
+
+            // Start the server on the port configured for Hugging Face Spaces
             .start(7860);
     }
 }