Migrate Redis from gson to jackson (#1694)

## Issue
Closes #1685 

## Change
Migrate `langchain4j-redis` from gson to jackson

## General checklist
<!-- Please double-check the following points and mark them like this:
[X] -->
- [x] There are no breaking changes
- [ ] I have added unit and integration tests for my change
- [x] I have manually run all the unit and integration tests in the
module I have added/changed, and they are all green
- [x] I have manually run all the unit and integration tests in the
[core](https://github.com/langchain4j/langchain4j/tree/main/langchain4j-core)
and
[main](https://github.com/langchain4j/langchain4j/tree/main/langchain4j)
modules, and they are all green
<!-- Before adding documentation and example(s) (below), please wait
until the PR is reviewed and approved. -->
- [ ] I have added/updated the
[documentation](https://github.com/langchain4j/langchain4j/tree/main/docs/docs)
- [ ] I have added an example in the [examples
repo](https://github.com/langchain4j/langchain4j-examples) (only for
"big" features)
- [ ] I have added/updated [Spring Boot
starter(s)](https://github.com/langchain4j/langchain4j-spring) (if
applicable)

langchain4j-redis/pom.xml

@@ -26,6 +26,11 @@
             <artifactId>jedis</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-api</artifactId>

langchain4j-redis/src/main/java/dev/langchain4j/store/embedding/redis/RedisEmbeddingStore.java

@@ -1,6 +1,7 @@
 package dev.langchain4j.store.embedding.redis;
 
-import com.google.gson.Gson;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import dev.langchain4j.data.document.Metadata;
 import dev.langchain4j.data.embedding.Embedding;
 import dev.langchain4j.data.segment.TextSegment;
@@ -13,6 +14,7 @@ import redis.clients.jedis.Pipeline;
 import redis.clients.jedis.json.Path2;
 import redis.clients.jedis.search.*;
 
+import java.io.IOException;
 import java.util.*;
 
 import static dev.langchain4j.internal.Utils.*;
@@ -33,7 +35,7 @@ import static redis.clients.jedis.search.RediSearchUtil.ToByteArray;
 public class RedisEmbeddingStore implements EmbeddingStore<TextSegment> {
 
     private static final Logger log = LoggerFactory.getLogger(RedisEmbeddingStore.class);
-    private static final Gson GSON = new Gson();
+    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
     private final JedisPooled client;
     private final RedisSchema schema;
@@ -206,7 +208,13 @@ public class RedisEmbeddingStore implements EmbeddingStore<TextSegment> {
                                 .collect(toMap(metadataKey -> metadataKey, document::getString));
                         embedded = new TextSegment(text, new Metadata(metadata));
                     }
-                    Embedding embedding = new Embedding(GSON.fromJson(document.getString(schema.vectorFieldName()), float[].class));
+                    Embedding embedding;
+                    try {
+                        float[] vectors = OBJECT_MAPPER.readValue(document.getString(schema.vectorFieldName()), float[].class);
+                        embedding = new Embedding(vectors);
+                    } catch (JsonProcessingException e) {
+                        throw new RedisRequestFailedException("failed to parse embedding", e);
+                    }
                     return new EmbeddingMatch<>(score, id, embedding, embedded);
                 })
                 .filter(embeddingMatch -> embeddingMatch.score() >= minScore)