Allow cross-origin requests

build.gradle

@@ -2,7 +2,7 @@ apply plugin: 'java'
 apply plugin: 'maven'
 
 group = 'net.cgro'
-version = '2019.1'
+version = '2019.2'
 
 description = """VoteManager"""
 

src/main/java/net/cgro/votemanager/MainApp.java

@@ -9,6 +9,7 @@
 import javafx.stage.WindowEvent;
 import net.cgro.votemanager.controller.MainWindowController;
 import net.cgro.votemanager.model.Wahl;
+import net.cgro.votemanager.util.CorsFilter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import spark.Spark;
@@ -27,7 +28,7 @@
 import java.util.Timer;
 import java.util.TimerTask;
 
-import static spark.Spark.get;
+import static spark.Spark.*;
 
 
 public class MainApp extends Application {
@@ -125,6 +126,7 @@ private void stopAutosave() {
     }
 
     private void startServer() {
+        CorsFilter.apply();
         get("/up", ((request, response) -> "up"));
         get("/status", (reqest, response) -> {
             response.type("text/xml; charset=utf-8");

src/main/java/net/cgro/votemanager/util/CorsFilter.java

@@ -0,0 +1,21 @@
+package net.cgro.votemanager.util;
+
+import spark.Filter;
+import spark.Spark;
+
+import java.util.HashMap;
+
+public final class CorsFilter {
+
+    private static final HashMap<String, String> corsHeaders = new HashMap<>();
+
+    static {
+        corsHeaders.put("Access-Control-Allow-Methods", "GET");
+        corsHeaders.put("Access-Control-Allow-Origin", "*");
+    }
+
+    public static void apply() {
+        Filter filter = (request, response) -> corsHeaders.forEach(response::header);
+        Spark.after(filter);
+    }
+}