使用Express返回GPT接口JSON响应异常：仅返回空对象{}

我用Node.js结合Express搭建服务，调用GPT接口生成文本摘要。函数能读取到数据，但服务器仅返回空对象{}。试过res.send(JSON.stringify(gptSummary(data)))和res.json等方式都无效，希望以JSON格式返回数据用于后续处理。相关代码如下：

相关代码 #

index.js #

import gptSummary from "./gptFunc.js";
import express from "express";

const app = express();

app.use(express.static("./public"));
app.use(express.urlencoded({ extended: true }));

app.post("/", async (req, res) => {
  let data = req.body.input;
  res.setHeader('Content-Type', 'application/json');
  res.send(JSON.stringify(gptSummary(data)));
});

app.listen(8080, () => {
  console.log("Server running on port 8080");
});

gptFunc.js #

import OpenAI from 'openai';

export default async function gptSummary(content){
    const openai = new OpenAI({
      apiKey: process.env.OPENAI_API_KEY
    });

    const chatCompletion = await openai.chat.completions.create({
      model: "gpt-3.5-turbo",
      messages:[{"role": "system", "content": "you must summarize the following text in a concise way. Do not include any extraneous information or add any additional information"}, {"role": "user", "content": content}],
    });
  let response = chatCompletion.choices[0].message;
  return response;
}

/public/index.html #

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <link rel="stylesheet" href="/static/style.css">
</head>
<body>
  <form method="post">
    <label for="input">Enter Text</label><br/>
    <input type="text" name="input" placeholder="type..."/>
    <input type="submit" value="generate">
  </form>
</body>
</html>

问题原因与解决方案 #

问题核心是未等待异步函数gptSummary执行完成。gptSummary是异步函数，直接调用会返回一个Promise对象，对Promise执行JSON.stringify会得到空对象{}，这就是服务器返回空内容的原因。

修改index.js中的POST路由逻辑，添加await等待异步结果，同时用res.json简化JSON返回操作：

app.post("/", async (req, res) => {
  let data = req.body.input;
  // 等待gptSummary异步执行完成，拿到实际结果
  const summaryResult = await gptSummary(data);
  // res.json自动处理JSON序列化与响应头设置
  res.json(summaryResult);
});

补充优化：添加错误处理 #

为避免异步调用失败导致服务器崩溃，建议增加错误捕获逻辑：

app.post("/", async (req, res) => {
  try {
    let data = req.body.input;
    const summaryResult = await gptSummary(data);
    res.json(summaryResult);
  } catch (error) {
    console.error("调用GPT接口失败:", error);
    res.status(500).json({ error: "生成摘要失败，请稍后重试" });
  }
});

内容的提问来源于stack exchange，提问作者Nebulous