Question

我使用rails，socket.io和节点构建了一个聊天服务器，允许用户相互发送图像，我正试图使用Amazon s3。以下是来自客户端和服务器的相关代码段：

客户端：

var img_file = this.files[0]; //retrieved from file input

file_reader.onload = function(e) {
    //console.log(img_file);
    var extension = img_file.name.split('.');
    extension = extension[extension.length-1];


    get_user_id(username, function(to_id) {
        socket.emit('message', {
            from: "<%= @user.displayname %>",
            fromid: <%= @user.id %>,
            to: username,
            toid: parseInt(to_id),
            content: e.target.result,
            type: 'image',
            extension: extension,
            size: img_file.size
        });
    })

};

file_reader.readAsBinaryString(img_file);

服务器：

socket.on('message', function(message) {
    console.log(message.type + " message received, sending to appropriate person: " + message.to);
    if (message.type == 'text') {
        //send message like normal
        sendMessage(message);           
    }
    else {
        //it's an image, need additional processing

        var blank_file = uuid.v4() + '-' + new Date().getTime() + '.' + message.extension;
        var contents = message.content;

        s3.putObject({
            Bucket: 'bucket-name', //not the real bucket name
            Key: blank_file,
            ContentType: 'image/' + message.extension,
            //ContentLength: message.size,
            Body: contents
        },
        function(err, data) {
            if (err) {
                console.log(err)
            }
            else {
                console.log('file uploaded to s3 successfully');

                message.content = getS3Url(blank_file);

                sendMessage(message);
            }
        })
    }
}

每当我尝试使用此代码上传图像时，它似乎都有效，但是当我检查我的s3存储桶并打开图像时，我的操作系统会说该文件不可读或已损坏。我尝试过使用ContentLength参数，但是当我使用它时，我收到错误“BadDigest：您指定的Content-MD5与我们收到的内容不匹配”。

任何人都可以帮助我吗？我让这段代码正常工作没有 s3，但由于某种原因，自从我开始使用它以来，我一直收到损坏或无法识别的文件。

Answer 1

I figured out what was wrong. You need to use a binary buffer to pass the data to s3 instead of just passing the string as is, so basically use these for the s3 parameters:

s3.putObject({
    Bucket: 'bucket-name',
    Key: file,
    Body: new Buffer(contents, 'binary') //use a buffer to pass the data over
}, function() { });

By using the buffer, it should upload the files properly.

S3在使用流时上传损坏的文件

1 个答案: