nodejs 网上下载图片到本地，并判断图片路径是否存在

var http = require("http");
var fs = require("fs");var server = http.createServer(function(req, res){}).listen(50082);
var url = "http://s0.hao123img.com/res/img/logo/logonew.png";//随机获取名称
function getName(){
var timer = new Date();
var arr = JSON.stringify(timer).replace(/:|-|"/g ,'').split('.');
var str = arr.join('');
console.log(str);
return str;
}load(url);
function load(url){
http.get(url, function(res){
var imgData = "";
res.setEncoding("binary"); //一定要设置response的编码为binary否则会下载下来的图片打不开
res.on("data", function(chunk){
imgData+=chunk;
});
res.on("end", function(){
if(imgData){
console.log('下载成功!');
var path = "./image/"+getName()+".png";
console.log(path);
fs.writeFile(path, imgData, "binary", function(err){
if(err){
console.log("down fail");
}
console.log("down success");
});
}else{
console.log('下载失败！,图片路径不存在！');
} });
});
}