nodejs base64 编码解码

普通字符串 编码解码:

var b = new Buffer('JavaScript'); var s = b.toString('base64'); 
// SmF2YVNjcmlwdA== var b = new Buffer('SmF2YVNjcmlwdA==', 'base64') var s = b.toString();
// JavaScript

　　

编码解码并转成hex

var b = new Buffer('SmF2YVNjcmlwdA==', 'base64') var s = b.toString('hex'); 
// 4a617661536372697074 var b = new Buffer('4a617661536372697074', 'hex') 
var s = b.toString('utf8');
// JavaScript

　　

编码解码图片

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');