Node.js 在s3映射问题中使用节点上载多个图像

我正在努力寻找将两个文件上传到s3的解决方案。我可以用multer上传一个文件，我已经学会了如何上传，但是当我试图在formdata中的所有文件中绘制一个地图并上传每个文件时，我会将每个位置的URL（我保存在数据库中的URL）放入一个数组中。然后，我尝试打印每个url，但令我惊讶的是，它们打印在if语句中，而不是当我将其保存在if之外的数据库中时。可能是因为一个不同步的问题吗？。 谢谢

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如果您查看文档，因为它不会返回承诺，所以您不应该打电话等待。默认映射方法与此表单中的异步代码不兼容。您需要使用异步代码，或者将其包装在承诺中，如

return await new Promise((resolve, reject) => {
...
    if (data) {
      fs.unlinkSync(item.path);
      resolve(data.location);
    }

}

---

您的其他代码也有一些问题。map函数应该返回一个值。如果您不想返回任何内容，则应使用foreach。

我已尝试解决此问题，但无法解决：( 这是我的新代码

tournamentsCtrl.createTournament = async (req, res) => {
    aws.config.setPromisesDependency();
    aws.config.update({
        accessKeyId: process.env.AWS_ACCESS_KEY_ID,
        secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
        //region: process.env.REGION
    });
    const s3 = new aws.S3();
    var files_upload = {};
    let promiseList = new Promise(function (resolve, reject) {
        req.files.forEach(element => {
            if (element.fieldname.includes('img')) {
                var folder = 'club_images'
            } else if (element.fieldname.inlcudes('poster')) {
                var folder = 'poster_tournament'
            } else {
                var folder = 'info_tournament'
            }
            var params = {
                ACL: 'public-read',
                Bucket: process.env.AWS_BUCKET_NAME,
                Body: fs.createReadStream(element.path),
                Key: `${folder + '/' + uuidv4() + element.fieldname}`
            };
            s3.upload(params, (err, data) => {
                if (err) {
                    console.log('Error occured while trying to upload to S3 bucket', err);
                }
                if (data) {
                    fs.unlinkSync(element.path); // Empty temp folder
                    const locationUrl = data.Location;
                    files_upload[element.fieldname] = locationUrl;
                    console.log(files_upload);
                }
            });
        });
        resolve(files_upload)
    })
    Promise.all([promiseList]).then(() => {
        console.log(Object.assign(JSON.parse(req.body.values), files_upload));
        const newUser = new Tournaments(Object.assign(JSON.parse(req.body.values), files_upload));
        console.log(newUser)
        newUser
            .save()
            .then(user => {
                res.json({ message: 'User created successfully', user });
            })
            .catch(err => {
                console.log('Error occured while trying to save to DB');
            });
    })
};

---

这是一个询问代码建议的不好的地方，但类似于以下内容

function uploadFile(s3, element) {
    return new Promise((resolve, reject) => {
        let folder;
        if (element.fieldname.includes('img')) {
            folder = 'club_images'
        } else if (element.fieldname.inlcudes('poster')) {
            folder = 'poster_tournament'
        } else {
            folder = 'info_tournament'
        }
        const params = {
            ACL: 'public-read',
            Bucket: process.env.AWS_BUCKET_NAME,
            Body: fs.createReadStream(element.path),
            Key: `${folder + '/' + uuidv4() + element.fieldname}`
        };
        s3.upload(params, (err, data) => {
            if (err) {
                return reject(err);
            }

            if (data) {
                return fs.unlink(element.path, err=> {
                    if(err) {
                        console.error("Failed to unlink file", element.path);
                    }
                    return resolve({[element.fieldname]: data.Location});
                }); // Empty temp folder
            }
            return resolve();

        });
    })
}

tournamentsCtrl.createTournament = async (req, res) => {
    aws.config.setPromisesDependency();
    aws.config.update({
        accessKeyId: process.env.AWS_ACCESS_KEY_ID,
        secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
        //region: process.env.REGION
    });
    const s3 = new aws.S3();

    try {
        const uploadData = await Promise.all(req.files.map(element => uploadFile(s3, element)));
        const returnData = Object.assign({}, ...uploadData);
        console.log(Object.assign(JSON.parse(req.body.values), returnData));
    } catch(e) {
        console.error('Failed to upload file', e);
        return res.sendStatus(500);
    }

    const newUser = new Tournaments(Object.assign(JSON.parse(req.body.values), files_upload));
    console.log(newUser)
    try {
        const user = await newUser.save()
        res.json({message: 'User created successfully', user});
    } catch(e) {
        console.error('Error occured while trying to save to DB');
        return res.sendStatus(500);
    }
};

---

谢谢你的回答。我试图解决它，但这是不可能的。你能帮我吗？谢谢。

function uploadFile(s3, element) {
    return new Promise((resolve, reject) => {
        let folder;
        if (element.fieldname.includes('img')) {
            folder = 'club_images'
        } else if (element.fieldname.inlcudes('poster')) {
            folder = 'poster_tournament'
        } else {
            folder = 'info_tournament'
        }
        const params = {
            ACL: 'public-read',
            Bucket: process.env.AWS_BUCKET_NAME,
            Body: fs.createReadStream(element.path),
            Key: `${folder + '/' + uuidv4() + element.fieldname}`
        };
        s3.upload(params, (err, data) => {
            if (err) {
                return reject(err);
            }

            if (data) {
                return fs.unlink(element.path, err=> {
                    if(err) {
                        console.error("Failed to unlink file", element.path);
                    }
                    return resolve({[element.fieldname]: data.Location});
                }); // Empty temp folder
            }
            return resolve();

        });
    })
}

tournamentsCtrl.createTournament = async (req, res) => {
    aws.config.setPromisesDependency();
    aws.config.update({
        accessKeyId: process.env.AWS_ACCESS_KEY_ID,
        secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
        //region: process.env.REGION
    });
    const s3 = new aws.S3();

    try {
        const uploadData = await Promise.all(req.files.map(element => uploadFile(s3, element)));
        const returnData = Object.assign({}, ...uploadData);
        console.log(Object.assign(JSON.parse(req.body.values), returnData));
    } catch(e) {
        console.error('Failed to upload file', e);
        return res.sendStatus(500);
    }

    const newUser = new Tournaments(Object.assign(JSON.parse(req.body.values), files_upload));
    console.log(newUser)
    try {
        const user = await newUser.save()
        res.json({message: 'User created successfully', user});
    } catch(e) {
        console.error('Error occured while trying to save to DB');
        return res.sendStatus(500);
    }
};