Migrated Bedrock from Gson to Jackson. (#1730)

## Issue
Closes #1687

## Change
Migrate Bedrock 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-bedrock/pom.xml

@@ -37,6 +37,11 @@
             <scope>provided</scope>
         </dependency>
 
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>

langchain4j-bedrock/src/main/java/dev/langchain4j/model/bedrock/BedrockAnthropicMessageChatModel.java

@@ -11,7 +11,7 @@ import dev.langchain4j.data.message.Content;
 import dev.langchain4j.data.message.ImageContent;
 import dev.langchain4j.data.message.TextContent;
 import dev.langchain4j.data.message.UserMessage;
-import dev.langchain4j.internal.Json;
+import dev.langchain4j.model.bedrock.internal.Json;
 import dev.langchain4j.model.bedrock.internal.AbstractBedrockChatModel;
 import dev.langchain4j.model.output.Response;
 import java.util.Collections;

langchain4j-bedrock/src/main/java/dev/langchain4j/model/bedrock/BedrockMistralAiChatModel.java

@@ -4,7 +4,7 @@ import static dev.langchain4j.internal.RetryUtils.withRetry;
 
 import dev.langchain4j.data.message.AiMessage;
 import dev.langchain4j.data.message.ChatMessage;
-import dev.langchain4j.internal.Json;
+import dev.langchain4j.model.bedrock.internal.Json;
 import dev.langchain4j.model.bedrock.internal.AbstractBedrockChatModel;
 import dev.langchain4j.model.output.Response;
 import java.util.HashMap;

langchain4j-bedrock/src/main/java/dev/langchain4j/model/bedrock/internal/AbstractBedrockChatModel.java

@@ -1,30 +1,21 @@
 package dev.langchain4j.model.bedrock.internal;
 
+import static dev.langchain4j.internal.RetryUtils.withRetry;
+
 import dev.langchain4j.data.message.AiMessage;
 import dev.langchain4j.data.message.ChatMessage;
-import dev.langchain4j.data.message.ChatMessageType;
-import dev.langchain4j.internal.Json;
 import dev.langchain4j.model.chat.ChatLanguageModel;
 import dev.langchain4j.model.output.Response;
-import lombok.Builder;
-import lombok.Getter;
-import lombok.experimental.SuperBuilder;
-import software.amazon.awssdk.auth.credentials.AwsCredentialsProvider;
-import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider;
-import software.amazon.awssdk.core.SdkBytes;
-import software.amazon.awssdk.regions.Region;
-import software.amazon.awssdk.services.bedrockruntime.BedrockRuntimeAsyncClient;
-import software.amazon.awssdk.services.bedrockruntime.BedrockRuntimeClient;
-import software.amazon.awssdk.services.bedrockruntime.model.InvokeModelRequest;
-import software.amazon.awssdk.services.bedrockruntime.model.InvokeModelResponse;
-
 import java.nio.charset.Charset;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-
+import lombok.Getter;
-import static dev.langchain4j.internal.RetryUtils.withRetry;
+import lombok.experimental.SuperBuilder;
-import static java.util.stream.Collectors.joining;
+import software.amazon.awssdk.core.SdkBytes;
+import software.amazon.awssdk.services.bedrockruntime.BedrockRuntimeClient;
+import software.amazon.awssdk.services.bedrockruntime.model.InvokeModelRequest;
+import software.amazon.awssdk.services.bedrockruntime.model.InvokeModelResponse;
 
 /**
  * Bedrock chat model

langchain4j-bedrock/src/main/java/dev/langchain4j/model/bedrock/internal/AbstractBedrockEmbeddingModel.java

@@ -1,11 +1,18 @@
 package dev.langchain4j.model.bedrock.internal;
 
+import static dev.langchain4j.internal.RetryUtils.withRetry;
+
 import dev.langchain4j.data.embedding.Embedding;
 import dev.langchain4j.data.segment.TextSegment;
-import dev.langchain4j.internal.Json;
 import dev.langchain4j.model.embedding.EmbeddingModel;
 import dev.langchain4j.model.output.Response;
 import dev.langchain4j.model.output.TokenUsage;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
 import lombok.Builder;
 import lombok.Getter;
 import lombok.experimental.SuperBuilder;
@@ -17,15 +24,6 @@ import software.amazon.awssdk.services.bedrockruntime.BedrockRuntimeClient;
 import software.amazon.awssdk.services.bedrockruntime.model.InvokeModelRequest;
 import software.amazon.awssdk.services.bedrockruntime.model.InvokeModelResponse;
 
-import java.nio.charset.Charset;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
-
-import static dev.langchain4j.internal.RetryUtils.withRetry;
-
 /**
  * Abstract bedrock embedding model
  */

langchain4j-bedrock/src/main/java/dev/langchain4j/model/bedrock/internal/AbstractBedrockStreamingChatModel.java

@@ -1,13 +1,13 @@
 package dev.langchain4j.model.bedrock.internal;
 
-import dev.langchain4j.agent.tool.ToolSpecification;
 import dev.langchain4j.data.message.AiMessage;
 import dev.langchain4j.data.message.ChatMessage;
 import dev.langchain4j.data.message.UserMessage;
-import dev.langchain4j.internal.Json;
 import dev.langchain4j.model.StreamingResponseHandler;
 import dev.langchain4j.model.chat.StreamingChatLanguageModel;
 import dev.langchain4j.model.output.Response;
+import java.util.ArrayList;
+import java.util.List;
 import lombok.Getter;
 import lombok.experimental.SuperBuilder;
 import software.amazon.awssdk.core.SdkBytes;
@@ -15,10 +15,6 @@ import software.amazon.awssdk.services.bedrockruntime.BedrockRuntimeAsyncClient;
 import software.amazon.awssdk.services.bedrockruntime.model.InvokeModelWithResponseStreamRequest;
 import software.amazon.awssdk.services.bedrockruntime.model.InvokeModelWithResponseStreamResponseHandler;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.atomic.AtomicReference;
-
 /**
  * Bedrock Streaming chat model
  */
@@ -28,7 +24,7 @@ public abstract class AbstractBedrockStreamingChatModel extends AbstractSharedBe
     @Getter
     private final BedrockRuntimeAsyncClient asyncClient = initAsyncClient();
 
-    class StreamingResponse {
+    static class StreamingResponse {
         public String completion;
     }
 

langchain4j-bedrock/src/main/java/dev/langchain4j/model/bedrock/internal/AbstractSharedBedrockChatModel.java

@@ -1,21 +1,18 @@
 package dev.langchain4j.model.bedrock.internal;
 
+import static java.util.stream.Collectors.joining;
+
 import dev.langchain4j.data.message.ChatMessage;
 import dev.langchain4j.data.message.ChatMessageType;
-import dev.langchain4j.internal.Json;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import lombok.Builder;
 import lombok.Getter;
 import lombok.experimental.SuperBuilder;
 import software.amazon.awssdk.auth.credentials.AwsCredentialsProvider;
 import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider;
 import software.amazon.awssdk.regions.Region;
-import software.amazon.awssdk.services.bedrockruntime.BedrockRuntimeClient;
-
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-import static java.util.stream.Collectors.joining;
 
 @Getter
 @SuperBuilder

langchain4j-bedrock/src/main/java/dev/langchain4j/model/bedrock/internal/Json.java

@@ -0,0 +1,32 @@
+package dev.langchain4j.model.bedrock.internal;
+
+import static com.fasterxml.jackson.databind.SerializationFeature.INDENT_OUTPUT;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class Json {
+  
+  static final ObjectMapper OBJECT_MAPPER = new ObjectMapper()
+      .enable(INDENT_OUTPUT)
+      .disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+      .setSerializationInclusion(JsonInclude.Include.NON_NULL);
+  
+  public static String toJson(Object o) {
+    try {
+      return OBJECT_MAPPER.writeValueAsString(o);
+    } catch (JsonProcessingException e) {
+      throw new RuntimeException(e);
+    }
+  }
+  
+  public static <T> T fromJson(String json, Class<T> type) {
+    try {
+      return OBJECT_MAPPER.readValue(json, type);
+    } catch (JsonProcessingException e) {
+      throw new RuntimeException(e);
+    }
+  }
+}