Base64 Nodejs 中的读取文件

Question

I'm trying to read an image from client side encoded in base64. How to read with nodejs?

My code:

// add to buffer base64 image
var encondedImage = new Buffer(image.name, 'base64');

fs.readFile(encondedImage, "base64", function(err, buffer){
    if ( err ) {
        console.log('In read file')
        console.log(err)
    } else {
        // check err
        lwip.open(buffer, 'jpg', function(err, image){
            console.log('in open')
            if ( err ) console.log(err)

            if ( image ) console.log(image)
            // check 'err'. use 'image'.
            // image.resize(...), etc.
        });
    }
})

But, I got this error:

In read file
[Error: Path must be a string without null bytes.]

Answer 1

Latest and greatest way to do this:

Node supports file and buffer operations with the base64 encoding :

const fs = require('fs');
const contents = fs.readFileSync('/path/to/file.jpg', {encoding: 'base64'});

Or using the new promises API :

const fs = require('fs').promises;
const contents = await fs.readFile('/path/to/file.jpg', {encoding: 'base64'});

Answer 2

I think that the following example demonstrates what you need: http://www.hacksparrow.com/base64-encoding-decoding-in-node-js.html

The essence of the article is this code part:

var fs = require('fs');

// function to encode file data to base64 encoded string
function base64_encode(file) {
    // read binary data
    var bitmap = fs.readFileSync(file);
    // convert binary data to base64 encoded string
    return new Buffer(bitmap).toString('base64');
}

// function to create file from base64 encoded string
function base64_decode(base64str, file) {
    // create buffer object from base64 encoded string, it is important to tell the constructor that the string is base64 encoded
    var bitmap = new Buffer(base64str, 'base64');
    // write buffer to file
    fs.writeFileSync(file, bitmap);
    console.log('******** File created from base64 encoded string ********');
}

// convert image to base64 encoded string
var base64str = base64_encode('kitten.jpg');
console.log(base64str);
// convert base64 string back to image 
base64_decode(base64str, 'copy.jpg');

Answer 3

var fs = require('fs');

function base64Encode(file) {
    var body = fs.readFileSync(file);
    return body.toString('base64');
}


var base64String = base64Encode('test.jpg');
console.log(base64String);