nodejs 上传附件到亚马逊s3

骑猪看日落 2022-04-02 03:25 315阅读 0赞

最近刚接手一个nodejs项目 前后端分离 前台angularjs1.5 后端node 项目里的附件上传都是上传到亚马逊s3云存储

## 使用 ##

### 1，安装aws sdk ###

npm install aws-sdk

### 2,配置参数 ###

var AWS = require('aws-sdk');
    AWS.config.loadFromPath('./config/config.json');
    var s3 = new AWS.S3({signatureVersion: 'v4', region:'ap-southeast-1'});

### 3，上传操作 ###

### 3.1 , 上传附件 ###

前台上传附件代码表单跳过

后端接受数据使用 formidable 组件 npm install formidable   var formidable = require("formidable")

upload.js 文件：

### 3.2,显示图片（获取图片访问url) ###

s3上面的路径为之前上传设定的路径 'supportFile/'+data\[0\].id+'/'+Date.now()+file.name

并将这个路径存到数据库中

可以使用s3 提供的 getSignedUrl  api  来获取图片url (官方文档[https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3.html\#getObject-property][https_docs.aws.amazon.com_AWSJavaScriptSDK_latest_AWS_S3.html_getObject-property]）

代码如下：

var params = {Bucket: config.bucket, Key: sqldata[0].filename1};//sqldata[0].filename1 为从数据库中读取的路径 supportFile/12/2019-02-03-filename.jep
    //必须参数 bucket 
    //key   s3指定文件的路径
    var url = s3.getSignedUrl('getObject', params);
    //得到一个加密的url

获取到路径之后 base64加密 就可以在前端 img中使用了

base64Img.requestBase64(url, function(err, result, body) {
    //nnpm install base64-img --save
              res.json({ "success": true, data: body });
         });

### 3.3,点击图片下载图片 ###

exports.download = function (req, res) {
        var email = req.decoded.email;
        let sql = mysql.format("SELECT * FROM customer WHERE email =?", [email]);
        //let sql = "SELECT * FROM customer WHERE email ='" + req.decoded.email + "'";
        connection.query(sql, function (error, data) {
            if (error) {
                res.json({ success: false, message: "error", error: cm_cfg.errorFn(error) })
            } else if (data[0] == null || data[0] == undefined) {
                res.json({ success: false, message: "User not found" })
            } else {
                if (req.query.path == '' || req.query.path == null) {
                    res.json({ success: false, message: "Requested file not found" })
                } else {
                    var reqPath = req.body.path;
                    var str1 = reqPath.split("/");
                    if (data[0].id == str1[1] && str1[0] == 'kycFile') {
                        if (str1.length > 4) {
                            return res.json({ success: false, message: "Unauthorized folder access" })
                        }
                        // if (str1.length === 4 && str1[2] !== 'banks_documents') {
                        //     return res.json({ success: false, message: "Unauthorized folder access" })
                        // }
                        // var pathcheck = fs.existsSync(reqPath)
                        // //console.log(pathcheck)
                        // if (pathcheck == true) {
                        //     var file_path = path.resolve(reqPath);
                        //     res.download(file_path);
    
                        // } else {
                        //     res.json({ success: false, message: "Requested file not found" })
                        // }
                        var params = {
                            Bucket: config.bucket, 
                            Key: reqPath
                        };
                        res.attachment(reqPath);
                        //创建一个可读的流
                        var fileStream = s3.getObject(params).createReadStream();
                        if(fileStream){
                            //可读流写入到响应中
                            fileStream.pipe(res); 
                        }else{
                            res.json({ success: false, message: "Image requested for some other user" })
                        }
                    } else {
                        res.json({ success: false, message: "Image requested for some other user" })
                    }
                }
            }
        })
    }

![20181225105804389.png][]

[https_docs.aws.amazon.com_AWSJavaScriptSDK_latest_AWS_S3.html_getObject-property]: https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3.html#getObject-property
[20181225105804389.png]: /images/20220402/e9b46ad6a4cd4c98a00b2d031685ac01.png