BAEL-4234: example of JNI registerNatives() method (#11745)

* BAEL-4234: example of JNI registerNatives() method

* fixed formatting in the cpp file

* removed camelcase in test package name

java-native/src/main/java/com/baeldung/jni/RegisterNativesHelloWorldJNI.java

@@ -0,0 +1,18 @@
+package com.baeldung.jni;
+
+public class RegisterNativesHelloWorldJNI {
+
+    static {
+        System.loadLibrary("native");
+    }
+
+    public static void main(String[] args) {
+        RegisterNativesHelloWorldJNI helloWorldJNI = new RegisterNativesHelloWorldJNI();
+        helloWorldJNI.register();
+        helloWorldJNI.sayHello();
+    }
+
+    public native String sayHello();
+
+    public native void register();
+}