Change result type from string to json in appropriate cases

Author: Haarolean

api/src/main/java/io/kafbat/ui/serdes/builtin/mm2/CheckpointSerde.java

@@ -90,7 +90,7 @@ public Deserializer deserializer(String topic, Target target) {
 
             try {
               var result = OBJECT_MAPPER.writeValueAsString(map);
-              yield new DeserializeResult(result, DeserializeResult.Type.STRING, Map.of());
+              yield new DeserializeResult(result, DeserializeResult.Type.JSON, Map.of());
             } catch (JsonProcessingException e) {
               log.error("Error serializing record", e);
               throw new RuntimeException(e);
@@ -116,7 +116,7 @@ public Deserializer deserializer(String topic, Target target) {
 
             try {
               var result = OBJECT_MAPPER.writeValueAsString(map);
-              yield new DeserializeResult(result, DeserializeResult.Type.STRING, Map.of());
+              yield new DeserializeResult(result, DeserializeResult.Type.JSON, Map.of());
             } catch (JsonProcessingException e) {
               log.error("Error serializing record", e);
               throw new RuntimeException(e);

api/src/main/java/io/kafbat/ui/serdes/builtin/mm2/HeartbeatSerde.java

@@ -81,7 +81,7 @@ public Deserializer deserializer(String topic, Target target) {
 
             try {
               var result = OBJECT_MAPPER.writeValueAsString(map);
-              yield new DeserializeResult(result, DeserializeResult.Type.STRING, Map.of());
+              yield new DeserializeResult(result, DeserializeResult.Type.JSON, Map.of());
             } catch (JsonProcessingException e) {
               log.error("Error serializing record", e);
               throw new RuntimeException(e);

api/src/main/java/io/kafbat/ui/serdes/builtin/mm2/OffsetSyncSerde.java

@@ -77,7 +77,7 @@ public Deserializer deserializer(String topic, Target target) {
 
             try {
               var result = OBJECT_MAPPER.writeValueAsString(map);
-              yield new DeserializeResult(result, DeserializeResult.Type.STRING, Map.of());
+              yield new DeserializeResult(result, DeserializeResult.Type.JSON, Map.of());
             } catch (JsonProcessingException e) {
               log.error("Error serializing record", e);
               throw new RuntimeException(e);
@@ -93,7 +93,7 @@ public Deserializer deserializer(String topic, Target target) {
 
             try {
               var result = OBJECT_MAPPER.writeValueAsString(map);
-              yield new DeserializeResult(result, DeserializeResult.Type.STRING, Map.of());
+              yield new DeserializeResult(result, DeserializeResult.Type.JSON, Map.of());
             } catch (JsonProcessingException e) {
               log.error("Error serializing record", e);
               throw new RuntimeException(e);