feat(jdk17): add jep 398 Deprecate the Applet API for Removal demo

src/main/java/org/javademos/init/Java17.java

@@ -8,6 +8,7 @@
 import org.javademos.java17.jep356.RandomGenerators17;
 import org.javademos.java17.jep382.MacosRenderingPipelineDemo;
 import org.javademos.java17.jep391.MacOsAarch64PortDemo;
+import org.javademos.java17.jep398.DeprecateAppletApiForRemovalDemo;
 import org.javademos.java17.jep403.StronglyEncapsulateInternalsDemo;
 import org.javademos.java17.jep406.PatternMatchingForSwitchPreview;
 import org.javademos.java17.jep407.RemoveRmiActivationDemo;
@@ -41,6 +42,8 @@ public static ArrayList<IDemo> getDemos() {
         java17DemoPool.add(new MacosRenderingPipelineDemo());
         // JEP 391
         java17DemoPool.add(new MacOsAarch64PortDemo());
+        // JEP 398
+        java17DemoPool.add(new DeprecateAppletApiForRemovalDemo());
         // JEP 403
         java17DemoPool.add(new StronglyEncapsulateInternalsDemo());
         // JEP 406

src/main/java/org/javademos/java17/jep398/DeprecateAppletApiForRemovalDemo.java

@@ -0,0 +1,28 @@
+package org.javademos.java17.jep398;
+
+import org.javademos.commons.IDemo;
+
+/// Demo for JDK 17 feature JEP 398 - Deprecate the Applet API for Removal.
+///
+/// JEP history:
+/// - JDK 17: [JEP 398 - Deprecate the Applet API for Removal](https://openjdk.org/jeps/398)
+/// - JDK 9: [JEP 289 - Deprecate the Applet API](https://openjdk.org/jeps/289) (Initial step)
+///
+/// Further reading:
+/// - [Java applet - wiki page](https://en.wikipedia.org/wiki/Java_applet)
+///
+/// @author Alexander Schneider @ab-schneider
+public class DeprecateAppletApiForRemovalDemo implements IDemo {
+    @Override
+    public void demo() {
+        info(398);
+
+        // The Applet API (java.applet.Applet) existed to run Java code inside browsers via the NPAPI plug-in.
+        // As all major browsers removed NPAPI (Chrome 2015, Firefox 2017, Edge never),
+        // the API became unusable: deprecated in JDK 9 (JEP 289), marked for removal in JDK 17 (JEP 398),
+        // and removed in JDK 26 (JEP 504).
+        //
+        // In case remaining uses of these APIs do exist, developers can suppress compiler warnings
+        // via the @SuppressWarnings("removal") annotation or the -Xlint:-removal command-line option of the javac compiler.
+    }
+}

src/main/resources/JDK17Info.json

@@ -28,6 +28,14 @@
     "link": false,
     "code": false
   },
+  {
+    "jep": 398,
+    "jdk": 17,
+    "name": "JEP 398 - Deprecate the Applet API for Removal",
+    "dscr": "Deprecate the Applet API for removal. It is essentially irrelevant since all web-browser vendors have removed support for Java browser plug-ins",
+    "link": false,
+    "code": false
+  },
   {
     "jep": 403,
     "jdk": 17,