Javascript 如何发送从REST Api收到的PNG数据响应

您可以直接将流响应通过管道发送到客户端响应.这种方法不需要将图像保存在服务器上，并允许您将图像数据直接转发到客户端.

1. 确保在响应中设置正确的Content-Type标头，以通知客户端它正在接收图像.

2. 使用stream.pipeline方法处理从外部API到客户端响应的数据流.此方法自动处理资源清理和错误处理.

const axios = require('axios');
const express = require('express');
const app = express();
const stream = require('stream');

app.get('/your-route', async (req, res) => {
    try {
        const streamResponse = await axios({
            method: 'GET',
            responseType: 'stream',
            url: endPoint + requestRoute,,
            headers: {
                'Authorization': 'Bearer ' + _token 
            }
        });

        // Set the Content-Type header to image/png
        res.setHeader('Content-Type', 'image/png');

        // Use stream.pipeline to handle the streaming of data
        await stream.pipeline(
            streamResponse.data,
            res,
            (err) => {
                if (err) {
                    console.error('Pipeline failed.', err);
                    res.status(500).send('Streaming failed.');
                }
            }
        );
    } catch (error) {
        console.error('Request to external API failed.', error);
        res.status(500).send('Request to external API failed.');
    }
});

app.listen(3000, () => {
    console.log('Server is running on port 3000');
});