Make Generator classes non-instantiable (they are static utility classes).

Author: phipag

examples/powertools-examples-kafka/tools/src/main/java/org/demo/kafka/tools/GenerateAvroSamples.java

@@ -16,60 +16,66 @@
  */
 public class GenerateAvroSamples {
 
+    private GenerateAvroSamples() {
+        // Utility class
+    }
+
     public static void main(String[] args) throws IOException {
         // Create three different products
         AvroProduct product1 = new AvroProduct(1001, "Laptop", 999.99);
         AvroProduct product2 = new AvroProduct(1002, "Smartphone", 599.99);
         AvroProduct product3 = new AvroProduct(1003, "Headphones", 149.99);
-        
+
         // Serialize and encode each product
         String encodedProduct1 = serializeAndEncode(product1);
         String encodedProduct2 = serializeAndEncode(product2);
         String encodedProduct3 = serializeAndEncode(product3);
-        
+
         // Serialize and encode an integer key
         String encodedKey = serializeAndEncodeInteger(42);
-        
+
         // Print the results
         System.out.println("Base64 encoded Avro products for use in kafka-avro-event.json:");
         System.out.println("\nProduct 1 (with key):");
         System.out.println("key: \"" + encodedKey + "\",");
         System.out.println("value: \"" + encodedProduct1 + "\",");
-        
+
         System.out.println("\nProduct 2 (with key):");
         System.out.println("key: \"" + encodedKey + "\",");
         System.out.println("value: \"" + encodedProduct2 + "\",");
-        
+
         System.out.println("\nProduct 3 (without key):");
         System.out.println("key: null,");
         System.out.println("value: \"" + encodedProduct3 + "\",");
-        
+
         // Print a sample event structure
         System.out.println("\nSample event structure:");
         printSampleEvent(encodedKey, encodedProduct1, encodedProduct2, encodedProduct3);
     }
-    
+
     private static String serializeAndEncode(AvroProduct product) throws IOException {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         BinaryEncoder encoder = EncoderFactory.get().binaryEncoder(baos, null);
         DatumWriter<AvroProduct> writer = new SpecificDatumWriter<>(AvroProduct.class);
-        
+
         writer.write(product, encoder);
         encoder.flush();
-        
+
         return Base64.getEncoder().encodeToString(baos.toByteArray());
     }
-    
+
     private static String serializeAndEncodeInteger(Integer value) throws IOException {
         // For simple types like integers, we'll just convert to string and encode
         return Base64.getEncoder().encodeToString(value.toString().getBytes());
     }
-    
+
     private static void printSampleEvent(String key, String product1, String product2, String product3) {
         System.out.println("{\n" +
                 "  \"eventSource\": \"aws:kafka\",\n" +
-                "  \"eventSourceArn\": \"arn:aws:kafka:us-east-1:0123456789019:cluster/SalesCluster/abcd1234-abcd-cafe-abab-9876543210ab-4\",\n" +
-                "  \"bootstrapServers\": \"b-2.demo-cluster-1.a1bcde.c1.kafka.us-east-1.amazonaws.com:9092,b-1.demo-cluster-1.a1bcde.c1.kafka.us-east-1.amazonaws.com:9092\",\n" +
+                "  \"eventSourceArn\": \"arn:aws:kafka:us-east-1:0123456789019:cluster/SalesCluster/abcd1234-abcd-cafe-abab-9876543210ab-4\",\n"
+                +
+                "  \"bootstrapServers\": \"b-2.demo-cluster-1.a1bcde.c1.kafka.us-east-1.amazonaws.com:9092,b-1.demo-cluster-1.a1bcde.c1.kafka.us-east-1.amazonaws.com:9092\",\n"
+                +
                 "  \"records\": {\n" +
                 "    \"mytopic-0\": [\n" +
                 "      {\n" +

examples/powertools-examples-kafka/tools/src/main/java/org/demo/kafka/tools/GenerateJsonSamples.java

@@ -13,6 +13,10 @@
  */
 public class GenerateJsonSamples {
 
+    private GenerateJsonSamples() {
+        // Utility class
+    }
+
     public static void main(String[] args) throws IOException {
         // Create three different products
         Map<String, Object> product1 = new HashMap<>();

examples/powertools-examples-kafka/tools/src/main/java/org/demo/kafka/tools/GenerateProtobufSamples.java

@@ -14,6 +14,10 @@
  */
 public class GenerateProtobufSamples {
 
+    private GenerateProtobufSamples() {
+        // Utility class
+    }
+
     public static void main(String[] args) throws IOException {
         // Create a single product that will be used for all three scenarios
         ProtobufProduct product = ProtobufProduct.newBuilder()