Deserialisierung von Nachrichten unterschiedlichen Typs

diff --git a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
index 431041c..ddeb9d5 100644 (file)
--- a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
+++ b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
@@ -2,7 +2,6 @@ package de.juplo.kafka;
 
 import org.apache.kafka.clients.consumer.ConsumerRecord;
 import org.apache.kafka.clients.consumer.KafkaConsumer;
-import org.apache.kafka.common.serialization.LongDeserializer;
 import org.apache.kafka.common.serialization.StringDeserializer;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
@@ -20,7 +19,7 @@ import java.util.function.Consumer;
 public class ApplicationConfiguration
 {
   @Bean
-  public Consumer<ConsumerRecord<String, ClientMessage>> consumer()
+  public Consumer<ConsumerRecord<String, ValidMessage>> consumer()
   {
     return (record) ->
     {
@@ -29,10 +28,10 @@ public class ApplicationConfiguration
   }
 
   @Bean
-  public EndlessConsumer<String, ClientMessage> endlessConsumer(
-      KafkaConsumer<String, ClientMessage> kafkaConsumer,
+  public EndlessConsumer<String, ValidMessage> endlessConsumer(
+      KafkaConsumer<String, ValidMessage> kafkaConsumer,
       ExecutorService executor,
-      Consumer<ConsumerRecord<String, ClientMessage>> handler,
+      Consumer<ConsumerRecord<String, ValidMessage>> handler,
       ApplicationProperties properties)
   {
     return
@@ -51,7 +50,7 @@ public class ApplicationConfiguration
   }
 
   @Bean(destroyMethod = "close")
-  public KafkaConsumer<String, ClientMessage> kafkaConsumer(ApplicationProperties properties)
+  public KafkaConsumer<String, ValidMessage> kafkaConsumer(ApplicationProperties properties)
   {
     Properties props = new Properties();
 
@@ -62,7 +61,9 @@ public class ApplicationConfiguration
     props.put("metadata.max.age.ms", "1000");
     props.put("key.deserializer", StringDeserializer.class.getName());
     props.put("value.deserializer", JsonDeserializer.class.getName());
-    props.put(JsonDeserializer.TYPE_MAPPINGS, "message:" + ClientMessage.class.getName());
+    props.put(JsonDeserializer.TYPE_MAPPINGS,
+        "message:" + ClientMessage.class.getName() + "," +
+        "greeting:" + Greeting.class.getName());
     props.put(JsonDeserializer.TRUSTED_PACKAGES, "de.juplo.kafka");
 
     return new KafkaConsumer<>(props);

diff --git a/src/main/java/de/juplo/kafka/ClientMessage.java b/src/main/java/de/juplo/kafka/ClientMessage.java
index d18800b..a158907 100644 (file)
--- a/src/main/java/de/juplo/kafka/ClientMessage.java
+++ b/src/main/java/de/juplo/kafka/ClientMessage.java
@@ -1,11 +1,22 @@
 package de.juplo.kafka;
 
-import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+import lombok.ToString;
 
 
-@Data
-public class ClientMessage
+@Getter
+@Setter
+@EqualsAndHashCode
+@ToString
+public class ClientMessage extends ValidMessage
 {
   String client;
   String message;
+
+  ClientMessage()
+  {
+    super(Type.CLIENT_MESSAGE);
+  }
 }

diff --git a/src/main/java/de/juplo/kafka/Greeting.java b/src/main/java/de/juplo/kafka/Greeting.java
new file mode 100644 (file)
index 0000000..4421a50
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/Greeting.java
@@ -0,0 +1,21 @@
+package de.juplo.kafka;
+
+import lombok.*;
+
+import java.time.LocalDateTime;
+
+
+@Getter
+@Setter
+@EqualsAndHashCode
+@ToString
+public class Greeting extends ValidMessage
+{
+  String name;
+  LocalDateTime when;
+
+  public Greeting()
+  {
+    super(Type.GREETING);
+  }
+}

diff --git a/src/main/java/de/juplo/kafka/ValidMessage.java b/src/main/java/de/juplo/kafka/ValidMessage.java
new file mode 100644 (file)
index 0000000..217d8f3
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/ValidMessage.java
@@ -0,0 +1,14 @@
+package de.juplo.kafka;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+
+@RequiredArgsConstructor
+public abstract class ValidMessage
+{
+  enum Type { CLIENT_MESSAGE, GREETING }
+
+  @Getter
+  private final Type type;
+}

diff --git a/src/test/java/de/juplo/kafka/ApplicationTests.java b/src/test/java/de/juplo/kafka/ApplicationTests.java
index 62906b3..9169de0 100644 (file)
--- a/src/test/java/de/juplo/kafka/ApplicationTests.java
+++ b/src/test/java/de/juplo/kafka/ApplicationTests.java
@@ -21,11 +21,11 @@ import org.springframework.test.context.TestPropertySource;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
 
 import java.time.Duration;
+import java.time.LocalDateTime;
 import java.util.*;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 import java.util.function.BiConsumer;
-import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
@@ -57,7 +57,7 @@ class ApplicationTests
        @Autowired
        KafkaProducer<String, Bytes> kafkaProducer;
        @Autowired
-       KafkaConsumer<String, ClientMessage> kafkaConsumer;
+       KafkaConsumer<String, ValidMessage> kafkaConsumer;
        @Autowired
        KafkaConsumer<Bytes, Bytes> offsetConsumer;
        @Autowired
@@ -65,11 +65,11 @@ class ApplicationTests
        @Autowired
        ExecutorService executor;
 
-       Consumer<ConsumerRecord<String, ClientMessage>> testHandler;
-       EndlessConsumer<String, ClientMessage> endlessConsumer;
+       Consumer<ConsumerRecord<String, ValidMessage>> testHandler;
+       EndlessConsumer<String, ValidMessage> endlessConsumer;
        Map<TopicPartition, Long> oldOffsets;
        Map<TopicPartition, Long> newOffsets;
-       Set<ConsumerRecord<String, ClientMessage>> receivedRecords;
+       Set<ConsumerRecord<String, ValidMessage>> receivedRecords;
 
 
        /** Tests methods */
@@ -80,8 +80,20 @@ class ApplicationTests
        {
                send100Messages((partition, key, counter) ->
                {
-                       Bytes value = serialize(key, counter);
-                       return new ProducerRecord<>(TOPIC, partition, key, value);
+                       Bytes value;
+                       String type;
+
+                       if (counter%3 != 0)
+                       {
+                               value = serializeClientMessage(key, counter);
+                               type = "message";
+                       }
+                       else {
+                               value = serializeGreeting(key, counter);
+                               type = "greeting";
+                       }
+
+                       return toRecord(partition, key, value, type);
                });
 
                await("100 records received")
@@ -107,10 +119,28 @@ class ApplicationTests
        {
                send100Messages((partition, key, counter) ->
                {
-                       Bytes value = counter == 77
-                                       ? new Bytes(stringSerializer.serialize(TOPIC, "BOOM!"))
-                                       : serialize(key, counter);
-                       return new ProducerRecord<>(TOPIC, partition, key, value);
+                       Bytes value;
+                       String type;
+
+                       if (counter == 77)
+                       {
+                               value = serializeFooMessage(key, counter);
+                               type = "foo";
+                       }
+                       else
+                       {
+                               if (counter%3 != 0)
+                               {
+                                       value = serializeClientMessage(key, counter);
+                                       type = "message";
+                               }
+                               else {
+                                       value = serializeGreeting(key, counter);
+                                       type = "greeting";
+                               }
+                       }
+
+                       return toRecord(partition, key, value, type);
                });
 
                await("Consumer failed")
@@ -209,7 +239,6 @@ class ApplicationTests
                                ProducerRecord<String, Bytes> record =
                                                recordGenerator.generate(partition, Integer.toString(partition*10+key%2), ++i);
 
-                               record.headers().add("__TypeId__", "message".getBytes());
                                kafkaProducer.send(record, (metadata, e) ->
                                {
                                        if (metadata != null)
@@ -234,14 +263,31 @@ class ApplicationTests
                }
        }
 
-       Bytes serialize(String key, Long value)
+       ProducerRecord<String, Bytes> toRecord(int partition, String key, Bytes value, String type)
+       {
+               ProducerRecord<String, Bytes> record =
+                               new ProducerRecord<>(TOPIC, partition, key, value);
+               record.headers().add("__TypeId__", type.getBytes());
+               return record;
+       }
+
+       Bytes serializeClientMessage(String key, Long value)
        {
-               ClientMessage message = new ClientMessage();
-               message.setClient(key);
-               message.setMessage(value.toString());
+               TestClientMessage message = new TestClientMessage(key, value.toString());
                return new Bytes(valueSerializer.serialize(TOPIC, message));
        }
 
+       Bytes serializeGreeting(String key, Long value)
+       {
+               TestGreeting message = new TestGreeting(key, LocalDateTime.now());
+               return new Bytes(valueSerializer.serialize(TOPIC, message));
+       }
+
+       Bytes serializeFooMessage(String key, Long value)
+       {
+               TestFooMessage message = new TestFooMessage(key, value);
+               return new Bytes(valueSerializer.serialize(TOPIC, message));
+       }
 
        @BeforeEach
        public void init()
@@ -258,7 +304,7 @@ class ApplicationTests
                        newOffsets.put(tp, offset - 1);
                });
 
-               Consumer<ConsumerRecord<String, ClientMessage>> captureOffsetAndExecuteTestHandler =
+               Consumer<ConsumerRecord<String, ValidMessage>> captureOffsetAndExecuteTestHandler =
                                record ->
                                {
                                        newOffsets.put(
@@ -298,7 +344,7 @@ class ApplicationTests
        public static class Configuration
        {
                @Bean
-               Serializer<ClientMessage> serializer()
+               Serializer<ValidMessage> serializer()
                {
                        return new JsonSerializer<>();
                }

diff --git a/src/test/java/de/juplo/kafka/TestClientMessage.java b/src/test/java/de/juplo/kafka/TestClientMessage.java
new file mode 100644 (file)
index 0000000..0072121
--- /dev/null
+++ b/src/test/java/de/juplo/kafka/TestClientMessage.java
@@ -0,0 +1,12 @@
+package de.juplo.kafka;
+
+
+import lombok.Value;
+
+
+@Value
+public class TestClientMessage
+{
+  private final String client;
+  private final String message;
+}

diff --git a/src/test/java/de/juplo/kafka/TestFooMessage.java b/src/test/java/de/juplo/kafka/TestFooMessage.java
new file mode 100644 (file)
index 0000000..d8f4c65
--- /dev/null
+++ b/src/test/java/de/juplo/kafka/TestFooMessage.java
@@ -0,0 +1,12 @@
+package de.juplo.kafka;
+
+
+import lombok.Value;
+
+
+@Value
+public class TestFooMessage
+{
+  private final String client;
+  private final Long timestamp;
+}

diff --git a/src/test/java/de/juplo/kafka/TestGreeting.java b/src/test/java/de/juplo/kafka/TestGreeting.java
new file mode 100644 (file)
index 0000000..446e877
--- /dev/null
+++ b/src/test/java/de/juplo/kafka/TestGreeting.java
@@ -0,0 +1,13 @@
+package de.juplo.kafka;
+
+import lombok.Value;
+
+import java.time.LocalDateTime;
+
+
+@Value
+public class TestGreeting
+{
+  private final String name;
+  private final LocalDateTime when;
+}