用java写一个chatgpt的调用代码

由于目前还没有Java官方提供的GPT-3 API，以下代码是基于OpenAI提供的GPT-3 API示例进行的，仅供参考：

import java.io.*;
import java.net.*;
import java.util.*;
import org.json.simple.*;
import org.json.simple.parser.*;

public class ChatGPT {
    private static final String API_KEY = "YOUR_API_KEY";
    private static final String ENDPOINT = "https://api.openai.com/v1/engines/davinci-codex/completions";
    private static final String PROMPT = "Hello, how can I help you today?";

    public static void main(String[] args) throws Exception {
        String input = "";
        Scanner scanner = new Scanner(System.in);
        while (!input.equalsIgnoreCase("exit")) {
            System.out.print("You: ");
            input = scanner.nextLine();
            String response = getResponse(input);
            System.out.println("ChatGPT: " + response);
        }
    }

    private static String getResponse(String input) throws Exception {
        URL url = new URL(ENDPOINT);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "application/json");
        conn.setRequestProperty("Authorization", "Bearer " + API_KEY);
        conn.setDoOutput(true);

        JSONObject jsonRequest = new JSONObject();
        jsonRequest.put("prompt", PROMPT + "\nUser: " + input + "\nChatGPT:");

        OutputStream os = conn.getOutputStream();
        os.write(jsonRequest.toJSONString().getBytes());
        os.flush();

        if (conn.getResponseCode() != HttpURLConnection.HTTP_OK) {
            throw new RuntimeException("Failed : HTTP error code : " + conn.getResponseCode());
        }

        BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
        StringBuilder sb = new StringBuilder();
        String output;
        while ((output = br.readLine()) != null) {
            sb.append(output);
        }

        conn.disconnect();

        JSONObject jsonResponse = (JSONObject) new JSONParser().parse(sb.toString());
        JSONArray choices = (JSONArray) jsonResponse.get("choices");
        JSONObject choice = (JSONObject) choices.get(0);
        return choice.get("text").toString().trim();
    }
}

需要注意的是，此代码需要引入json-simple库，可以通过Maven或其他方式进行导入。同时，需要将API_KEY替换为你自己的API密钥。