Add getCodec method to StatefulConnection

src/main/java/io/lettuce/core/StatefulRedisConnectionImpl.java

@@ -109,6 +109,7 @@ public StatefulRedisConnectionImpl(RedisChannelWriter writer, PushHandler pushHa
         this.reactive = newRedisReactiveCommandsImpl();
     }
 
+    @Override
     public RedisCodec<K, V> getCodec() {
         return codec;
     }

src/main/java/io/lettuce/core/api/StatefulConnection.java

@@ -6,6 +6,7 @@
 
 import io.lettuce.core.ClientOptions;
 import io.lettuce.core.RedisConnectionStateListener;
+import io.lettuce.core.codec.RedisCodec;
 import io.lettuce.core.protocol.RedisCommand;
 import io.lettuce.core.resource.ClientResources;
 
@@ -81,7 +82,7 @@ public interface StatefulConnection<K, V> extends AutoCloseable, AsyncCloseable
      * connection will become not usable anymore as soon as this method was called.
      *
      * @return a {@link CompletableFuture} that is notified once the operation completes, either because the operation was
-     *         successful or because of an error.
+     * successful or because of an error.
      * @since 5.1
      */
     @Override
@@ -117,4 +118,9 @@ public interface StatefulConnection<K, V> extends AutoCloseable, AsyncCloseable
      */
     void flushCommands();
 
+    /**
+     * @return the codec used for this connection.
+     */
+    RedisCodec<K, V> getCodec();
+
 }

src/main/java/io/lettuce/core/cluster/StatefulRedisClusterConnectionImpl.java

@@ -126,6 +126,11 @@ public StatefulRedisClusterConnectionImpl(RedisChannelWriter writer, ClusterPush
         this.reactive = newRedisAdvancedClusterReactiveCommandsImpl();
     }
 
+    @Override
+    public RedisCodec<K, V> getCodec() {
+        return codec;
+    }
+
     protected RedisAdvancedClusterReactiveCommandsImpl<K, V> newRedisAdvancedClusterReactiveCommandsImpl() {
         return new RedisAdvancedClusterReactiveCommandsImpl<>((StatefulRedisClusterConnection<K, V>) this, codec, parser);
     }

src/main/java/io/lettuce/core/sentinel/StatefulRedisSentinelConnectionImpl.java

@@ -128,6 +128,11 @@ public ConnectionState getConnectionState() {
         return connectionState;
     }
 
+    @Override
+    public RedisCodec<K, V> getCodec() {
+        return codec;
+    }
+
     static class SentinelConnectionState extends ConnectionState {
 
         @Override