Add option to document an example for kafka key bindings, change structure of KafkaAsyncMessageBinding to contain a new sub-annotation KafkaAsyncKey to make it more obvious what is part of the key documentation and which is part of the kafka message binding, Add default values for message binding to KafkaConsumer- and KafkaProducerData

Author: sam0r040

springwolf-plugins/springwolf-kafka-plugin/src/main/java/io/github/stavshamir/springwolf/asyncapi/scanners/channels/operationdata/KafkaMessageBindingProcessor.java

@@ -49,12 +49,13 @@ private String resolveOrNull(String stringValue) {
 
     private Schema<?> resolveSchemaOrNull(KafkaAsyncMessageBinding messageBinding) {
         Schema<?> schemaDefinition = null;
-        switch (messageBinding.keyType()) {
-            case NO_KEY:
+        switch (messageBinding.key().type()) {
+            case UNDEFINED_KEY:
                 break;
             case STRING_KEY:
                 schemaDefinition = new StringSchema()
-                        .description(resolveOrNull(messageBinding.description()));
+                        .example(messageBinding.key().example())
+                        .description(resolveOrNull(messageBinding.key().description()));
         }
 
         return schemaDefinition;

springwolf-plugins/springwolf-kafka-plugin/src/main/java/io/github/stavshamir/springwolf/asyncapi/scanners/channels/operationdata/annotation/KafkaAsyncOperationBinding.java

@@ -26,14 +26,22 @@
     @Target({})
     @interface KafkaAsyncMessageBinding {
 
-        KafkaKeyTypes keyType() default KafkaKeyTypes.NO_KEY;
-
-        String description() default "";
+        KafkaAsyncKey key() default @KafkaAsyncKey(type = KafkaAsyncKey.KafkaKeyTypes.UNDEFINED_KEY);
 
         String bindingVersion() default "";
+    }
+    @Retention(RetentionPolicy.CLASS)
+    @Target({})
+    @interface KafkaAsyncKey {
+
+        KafkaKeyTypes type() default KafkaKeyTypes.STRING_KEY;
+
+        String example() default "";
+
+        String description() default "";
 
         enum KafkaKeyTypes {
-            NO_KEY,
+            UNDEFINED_KEY,
             STRING_KEY
         }
     }

springwolf-plugins/springwolf-kafka-plugin/src/main/java/io/github/stavshamir/springwolf/asyncapi/types/KafkaConsumerData.java

@@ -1,6 +1,7 @@
 package io.github.stavshamir.springwolf.asyncapi.types;
 
 import com.asyncapi.v2.binding.kafka.KafkaChannelBinding;
+import com.asyncapi.v2.binding.kafka.KafkaMessageBinding;
 import com.asyncapi.v2.binding.kafka.KafkaOperationBinding;
 import com.google.common.collect.ImmutableMap;
 import io.github.stavshamir.springwolf.asyncapi.types.channel.operation.message.header.AsyncHeaders;
@@ -15,5 +16,6 @@ public KafkaConsumerData(String topicName, Class<?> payloadType, String descript
         this.payloadType = payloadType;
         this.headers = headers != null ? headers : this.headers;
         this.operationBinding = ImmutableMap.of("kafka", new KafkaOperationBinding());
+        this.messageBinding = ImmutableMap.of("kafka", new KafkaMessageBinding());
     }
 }

springwolf-plugins/springwolf-kafka-plugin/src/main/java/io/github/stavshamir/springwolf/asyncapi/types/KafkaProducerData.java

@@ -1,6 +1,7 @@
 package io.github.stavshamir.springwolf.asyncapi.types;
 
 import com.asyncapi.v2.binding.kafka.KafkaChannelBinding;
+import com.asyncapi.v2.binding.kafka.KafkaMessageBinding;
 import com.asyncapi.v2.binding.kafka.KafkaOperationBinding;
 import com.google.common.collect.ImmutableMap;
 import io.github.stavshamir.springwolf.asyncapi.types.channel.operation.message.header.AsyncHeaders;
@@ -16,6 +17,7 @@ public KafkaProducerData(String topicName, Class<?> payloadType, String descript
         this.payloadType = payloadType;
         this.headers = headers != null ? headers : this.headers;
         this.operationBinding = ImmutableMap.of("kafka", new KafkaOperationBinding());
+        this.messageBinding = ImmutableMap.of("kafka", new KafkaMessageBinding());
     }
 
 }