ChatGPT API Javaバージョン

以下のコードでJavaでChatGPTのAPIにアクセスできます。

■Maven

<dependency>
	<groupId>com.google.code.gson</groupId>
	<artifactId>gson</artifactId>
	<version>2.8.8</version>
</dependency>

■Java

package com.example.controller;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;

@Controller
@RequestMapping("")
public class TestChatCompletionController {

	@RequestMapping("")
	public String openAIChat() {
		
        String url = "https://api.openai.com/v1/chat/completions";
        String api_key = System.getenv("OPENAI_API_KEY");
        String model = "gpt-3.5-turbo";
        String message = "{\"role\": \"user\", \"content\": \"Hello!\"}";

        try {
        	// HTTPリクエストの作成
            URL obj = new URL(url);
            HttpURLConnection con = (HttpURLConnection) obj.openConnection();
            con.setRequestMethod("POST");
            con.setRequestProperty("Content-Type", "application/json");
            con.setRequestProperty("Authorization", "Bearer " + api_key);
            con.setDoOutput(true);

            // リクエストの送信
            OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream());
            out.write("{\"model\": \"" + model + "\", \"messages\": [" + message + "]}");
            out.close();

            // レスポンスの取得
            BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            Gson gson = new Gson();
            JsonObject jsonResponse = gson.fromJson(in, JsonObject.class);
            JsonArray choicesArray = jsonResponse.getAsJsonArray("choices");
            JsonObject messageObject = choicesArray.get(0).getAsJsonObject().get("message").getAsJsonObject();
            String content = messageObject.get("content").getAsString();

            // レスポンスの出力
            System.out.println(content);
        } catch (Exception e) {
            System.out.println(e);
        }	
        return "start";
	}
}