nodejs 剪切图像在上传，并保存到指定路径下，./public/img/' + req.session.token + '.jpg‘

前jQuery端接收数据

function upAvatar(img){
console.log(img);  // data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAMCAgICAgMCAgIDAwMD…/7vA+eq/xZAlzs/wBYlP8AtlpRRXcc9h++B/8AVyJRs30UVRkM2e9M8s+tFFSBE6UUUUGp/9k=
    $.ajax({
        url:'/user/upload',
        type:'PUT',
        data:{
            imgData: img
        },
        success: function (){

 　　　　　　botbox.alert('上传成功！');

        },
        error: function (){
            bootbox.alert('上传失败，请稍后再试！');
        }
    });
}

Nodejs（express）后端接收数据

app.put('/user/upload',function(req,res){
    if(req.body.imgData){
        var avatar = req.body.imgData.replace(/^data:image\/\w+;base64,/, '');
        var fs = require('fs'),
            newBuff = new Buffer(avatar, 'base64');
        fs.writeFile('./public/img/' + req.session.token + '.jpg', newBuff, 'binary', function (err) {
            if (err){
                return res.sendStatus(500);
            }
            res.sendStatus(200);
        });
    }else{
        res.sendStatus(400);
    }
});