convert from gson to jackson

Author: CJCrafter

build.gradle.kts

@@ -19,7 +19,12 @@ repositories {
 
 dependencies {
     implementation("com.squareup.okhttp3:okhttp:4.9.2")
-    implementation("com.google.code.gson:gson:2.10.1")
+
+    implementation("com.fasterxml.jackson.core:jackson-core:2.15.3")
+    implementation("com.fasterxml.jackson.core:jackson-databind:2.15.3")
+    implementation("com.fasterxml.jackson.core:jackson-annotations:2.15.3")
+    implementation("com.fasterxml.jackson.module:jackson-module-kotlin:2.15.3")
+
     implementation("org.jetbrains:annotations:24.0.1")
 
     testImplementation("io.github.cdimascio:dotenv-kotlin:6.4.1")

src/main/kotlin/com/cjcrafter/openai/AzureOpenAI.kt

@@ -26,7 +26,7 @@ class AzureOpenAI @JvmOverloads constructor(
 ) : OpenAIImpl(apiKey, organization, client) {
 
     override fun buildRequest(request: Any, endpoint: String): Request {
-        val json = gson.toJson(request)
+        val json = objectMapper.writeValueAsString(request)
         val body: RequestBody = json.toRequestBody(mediaType)
         return Request.Builder()
             .url("$azureBaseUrl/openai/deployments/$modelName/$endpoint?api-version=$apiVersion")

src/main/kotlin/com/cjcrafter/openai/FinishReason.kt

@@ -1,6 +1,6 @@
 package com.cjcrafter.openai
 
-import com.google.gson.annotations.SerializedName
+import com.fasterxml.jackson.annotation.JsonProperty
 
 /**
  * [FinishReason] wraps the possible reasons that a generation model may stop
@@ -15,7 +15,7 @@ enum class FinishReason {
      * completely generates its entire message, and has nothing else to add.
      * Ideally, you always want your finish reason to be [STOP].
      */
-    @SerializedName("stop")
+    @JsonProperty("stop")
     STOP,
 
     /**
@@ -24,23 +24,23 @@ enum class FinishReason {
      * message with finish reason [LENGTH]. Some models have a higher token
      * limit than others.
      */
-    @SerializedName("length")
+    @JsonProperty("length")
     LENGTH,
 
     /**
      * Occurs due to a flag from OpenAI's content filters. This occurrence is
      * rare, and tends to happen when you blatantly violate OpenAI's terms.
      */
-    @SerializedName("content_filter")
+    @JsonProperty("content_filter")
     CONTENT_FILTER,
 
     /**
      * Occurs when the model uses one of the available tools.
      */
-    @SerializedName("tool_calls")
+    @JsonProperty("tool_calls")
     TOOL_CALLS,
 
     @Deprecated("functions have been replaced by tools")
-    @SerializedName("function_call")
+    @JsonProperty("function_call")
     FUNCTION_CALL;
 }

src/main/kotlin/com/cjcrafter/openai/OpenAI.kt

@@ -5,8 +5,15 @@ import com.cjcrafter.openai.chat.tool.ToolChoice
 import com.cjcrafter.openai.completions.CompletionRequest
 import com.cjcrafter.openai.completions.CompletionResponse
 import com.cjcrafter.openai.completions.CompletionResponseChunk
-import com.google.gson.Gson
-import com.google.gson.GsonBuilder
+import com.cjcrafter.openai.jackson.ChatChoiceChunkDeserializer
+import com.cjcrafter.openai.jackson.ChatChoiceChunkSerializer
+import com.cjcrafter.openai.jackson.ToolChoiceDeserializer
+import com.cjcrafter.openai.jackson.ToolChoiceSerializer
+import com.fasterxml.jackson.annotation.JsonInclude
+import com.fasterxml.jackson.databind.DeserializationFeature
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.module.SimpleModule
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import okhttp3.OkHttpClient
 
 interface OpenAI {
@@ -129,22 +136,22 @@ interface OpenAI {
         fun azureBuilder() = AzureBuilder()
 
         /**
-         * Returns a Gson instance with the default OpenAI adapters registered.
+         * Returns an ObjectMapper instance with the default OpenAI adapters registered.
          * This can be used to save conversations (and other data) to file.
          */
-        @JvmStatic
-        fun createGson(): Gson = createGsonBuilder().create()
-
-        /**
-         * Returns a GsonBuilder instance with the default OpenAI adapters
-         * registered.
-         */
-        @JvmStatic
-        fun createGsonBuilder(): GsonBuilder {
-            return GsonBuilder()
-                .serializeNulls()
-                .registerTypeAdapter(ChatChoiceChunk::class.java, ChatChoiceChunk.adapter())
-                .registerTypeAdapter(ToolChoice::class.java, ToolChoice.adapter())
+        fun createObjectMapper(): ObjectMapper = jacksonObjectMapper().apply {
+            setSerializationInclusion(JsonInclude.Include.NON_NULL)
+            configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
+
+            // Register modules with custom serializers/deserializers
+            val module = SimpleModule().apply {
+                addSerializer(ChatChoiceChunk::class.java, ChatChoiceChunkSerializer())
+                addDeserializer(ChatChoiceChunk::class.java, ChatChoiceChunkDeserializer())
+                addSerializer(ToolChoice::class.java, ToolChoiceSerializer())
+                addDeserializer(ToolChoice::class.java, ToolChoiceDeserializer())
+            }
+
+            registerModule(module)
         }
 
         /**

src/main/kotlin/com/cjcrafter/openai/OpenAIImpl.kt

@@ -5,9 +5,7 @@ import com.cjcrafter.openai.completions.CompletionRequest
 import com.cjcrafter.openai.completions.CompletionResponse
 import com.cjcrafter.openai.completions.CompletionResponseChunk
 import com.cjcrafter.openai.completions.CompletionUsage
-import com.cjcrafter.openai.exception.WrappedIOError
-import com.google.gson.JsonObject
-import com.google.gson.JsonParser
+import com.fasterxml.jackson.databind.node.ObjectNode
 import okhttp3.*
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.RequestBody.Companion.toRequestBody
@@ -55,10 +53,10 @@ open class OpenAIImpl @JvmOverloads constructor(
     private val client: OkHttpClient = OkHttpClient()
 ): OpenAI {
     protected val mediaType = "application/json; charset=utf-8".toMediaType()
-    protected val gson = OpenAI.createGson()
+    protected val objectMapper = OpenAI.createObjectMapper()
 
     protected open fun buildRequest(request: Any, endpoint: String): Request {
-        val json = gson.toJson(request)
+        val json = objectMapper.writeValueAsString(request)
         val body: RequestBody = json.toRequestBody(mediaType)
         return Request.Builder()
             .url("https://api.openai.com/$endpoint")
@@ -73,12 +71,8 @@ open class OpenAIImpl @JvmOverloads constructor(
         request.stream = false // use streamCompletion for stream=true
         val httpRequest = buildRequest(request, COMPLETIONS_ENDPOINT)
 
-        try {
-            val httpResponse = client.newCall(httpRequest).execute()
-            println(httpResponse)
-        } catch (ex: IOException) {
-            throw WrappedIOError(ex)
-        }
+        val httpResponse = client.newCall(httpRequest).execute()
+        println(httpResponse)
 
         return CompletionResponse("1", 1, "1", listOf(), CompletionUsage(1, 1, 1))
     }
@@ -104,7 +98,7 @@ open class OpenAIImpl @JvmOverloads constructor(
         }
 
         val json = httpResponse.body?.byteStream()?.bufferedReader() ?: throw IOException("Response body is null")
-        return gson.fromJson(json, ChatResponse::class.java)
+        return objectMapper.readValue(json, ChatResponse::class.java)
     }
 
     override fun streamChatCompletion(request: ChatRequest): Iterable<ChatResponseChunk> {
@@ -150,7 +144,7 @@ open class OpenAIImpl @JvmOverloads constructor(
                     override fun next(): ChatResponseChunk {
                         val currentLine = nextLine ?: throw NoSuchElementException("No more lines")
                         //println("         $currentLine")
-                        chunk = chunk?.apply { update(JsonParser.parseString(currentLine).asJsonObject) } ?: gson.fromJson(currentLine, ChatResponseChunk::class.java)
+                        chunk = chunk?.apply { update(objectMapper.readTree(currentLine) as ObjectNode) } ?: objectMapper.readValue(currentLine, ChatResponseChunk::class.java)
                         nextLine = readNextLine(reader) // Prepare the next line
                         return chunk!!
                     }
@@ -159,8 +153,6 @@ open class OpenAIImpl @JvmOverloads constructor(
         }
     }
 
-
-
     companion object {
         const val COMPLETIONS_ENDPOINT = "v1/completions"
         const val CHAT_ENDPOINT = "v1/chat/completions"

src/main/kotlin/com/cjcrafter/openai/chat/ChatChoice.kt

@@ -1,8 +1,7 @@
 package com.cjcrafter.openai.chat
 
 import com.cjcrafter.openai.FinishReason
-import com.google.gson.JsonObject
-import com.google.gson.annotations.SerializedName
+import com.fasterxml.jackson.annotation.JsonProperty
 
 /**
  * The OpenAI API returns a list of `ChatChoice`. Each choice has a
@@ -24,5 +23,5 @@ import com.google.gson.annotations.SerializedName
 data class ChatChoice(
     val index: Int,
     val message: ChatMessage,
-    @field:SerializedName("finish_reason") val finishReason: FinishReason
+    @JsonProperty("finish_reason") val finishReason: FinishReason
 )

src/main/kotlin/com/cjcrafter/openai/chat/ChatChoiceChunk.kt

@@ -1,9 +1,11 @@
 package com.cjcrafter.openai.chat
 
 import com.cjcrafter.openai.FinishReason
-import com.cjcrafter.openai.gson.ChatChoiceChunkAdapter
-import com.google.gson.JsonObject
-import com.google.gson.annotations.SerializedName
+import com.cjcrafter.openai.jackson.ChatChoiceChunkDeserializer
+import com.cjcrafter.openai.jackson.ChatChoiceChunkSerializer
+import com.fasterxml.jackson.annotation.JsonProperty
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 
 /**
  *
@@ -29,14 +31,22 @@ data class ChatChoiceChunk(
     val index: Int,
     val message: ChatMessage,
     var delta: String,
-    @field:SerializedName("finish_reason") var finishReason: FinishReason?
+    @JsonProperty("finish_reason") var finishReason: FinishReason?
 ) {
 
-    internal fun update(json: JsonObject)  {
-        val deltaJson = json["delta"].asJsonObject
-        delta = if (deltaJson.has("content")) deltaJson["content"].asString else ""
+    internal fun update(json: String) {
+        val node: JsonNode = jacksonObjectMapper().readTree(json)
+        val deltaNode = node.get("delta")
+        delta = if (deltaNode?.has("content") == true && !deltaNode.get("content").isNull) {
+            deltaNode.get("content").asText()
+        } else {
+            ""
+        }
+
         message.content += delta
-        finishReason = if (json["finish_reason"].isJsonNull) null else FinishReason.valueOf(json["finish_reason"].asString.uppercase())
+        finishReason = node.get("finish_reason")?.takeIf { !it.isNull }?.asText()?.let {
+            FinishReason.valueOf(it.uppercase())
+        }
     }
 
     /**
@@ -48,7 +58,10 @@ data class ChatChoiceChunk(
 
     companion object {
         @JvmStatic
-        fun adapter() = ChatChoiceChunkAdapter()
+        fun serializer() = ChatChoiceChunkSerializer()
+
+        @JvmStatic
+        fun deserializer() = ChatChoiceChunkDeserializer()
     }
 }
 

src/main/kotlin/com/cjcrafter/openai/chat/ChatMessage.kt

@@ -1,7 +1,8 @@
 package com.cjcrafter.openai.chat
 
 import com.cjcrafter.openai.chat.tool.ToolCall
-import com.google.gson.annotations.SerializedName
+import com.fasterxml.jackson.annotation.JsonInclude
+import com.fasterxml.jackson.annotation.JsonProperty
 
 /**
  * ChatGPT's biggest innovation is its conversation memory. To remember the
@@ -14,9 +15,9 @@ import com.google.gson.annotations.SerializedName
  */
 data class ChatMessage @JvmOverloads constructor(
     var role: ChatUser,
-    var content: String?,
-    @field:SerializedName("tool_calls") var toolCalls: List<ToolCall>? = null,
-    @field:SerializedName("tool_call_id") var toolCallId: String? = null,
+    @JsonInclude var content: String?, // JsonInclude here is important for tools
+    @JsonProperty("tool_calls") var toolCalls: List<ToolCall>? = null,
+    @JsonProperty("tool_call_id") var toolCallId: String? = null,
 ) {
     init {
         if (role == ChatUser.TOOL) {

src/main/kotlin/com/cjcrafter/openai/chat/ChatRequest.kt

@@ -3,24 +3,24 @@ package com.cjcrafter.openai.chat
 import com.cjcrafter.openai.chat.tool.AbstractTool
 import com.cjcrafter.openai.chat.tool.Tool
 import com.cjcrafter.openai.chat.tool.ToolChoice
-import com.google.gson.annotations.SerializedName
+import com.fasterxml.jackson.annotation.JsonProperty
 
 data class ChatRequest @JvmOverloads internal constructor(
     var messages: MutableList<ChatMessage>,
     var model: String,
-    @field:SerializedName("frequency_penalty") var frequencyPenalty: Float? = null,
-    @field:SerializedName("logit_bias") var logitBias: MutableMap<String, Float>? = null,
-    @field:SerializedName("max_tokens") var maxTokens: Int? = null,
+    @JsonProperty("frequency_penalty") var frequencyPenalty: Float? = null,
+    @JsonProperty("logit_bias") var logitBias: MutableMap<String, Float>? = null,
+    @JsonProperty("max_tokens") var maxTokens: Int? = null,
     var n: Int? = null,
-    @field:SerializedName("presence_penalty") var presencePenalty: Float? = null,
-    @field:SerializedName("response_format") var responseFormat: ChatResponseFormat? = null,
+    @JsonProperty("presence_penalty") var presencePenalty: Float? = null,
+    @JsonProperty("response_format") var responseFormat: ChatResponseFormat? = null,
     var seed: Int? = null,
     var stop: String? = null,
     @Deprecated("Use OpenAI#streamChatCompletion") var stream: Boolean? = null,
     var temperature: Float? = null,
-    @field:SerializedName("top_p") var topP: Float? = null,
+    @JsonProperty("top_p") var topP: Float? = null,
     var tools: MutableList<Tool>? = null,
-    @field:SerializedName("tool_choice") var toolChoice: ToolChoice? = null,
+    @JsonProperty("tool_choice") var toolChoice: ToolChoice? = null,
     var user: String? = null,
 ) {
 

src/main/kotlin/com/cjcrafter/openai/chat/ChatResponseChunk.kt

@@ -1,6 +1,9 @@
 package com.cjcrafter.openai.chat
 
-import com.google.gson.JsonObject
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.databind.node.ArrayNode
+import com.fasterxml.jackson.databind.node.ObjectNode
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import java.time.Instant
 import java.time.ZoneId
 import java.time.ZonedDateTime
@@ -26,10 +29,10 @@ data class ChatResponseChunk(
     val created: Long,
     val choices: List<ChatChoiceChunk>,
 ) {
-
-    internal fun update(json: JsonObject) {
-        json["choices"].asJsonArray.forEachIndexed { index, jsonElement ->
-            choices[index].update(jsonElement.asJsonObject)
+    internal fun update(json: ObjectNode) {
+        val choicesArray = json.get("choices") as? ArrayNode
+        choicesArray?.forEachIndexed { index, jsonNode ->
+            choices[index].update(jsonNode.toString())
         }
     }