NodeJs实现简易WEB上传下载服务器

Z时代
2024-01-10
分类：综合

项目上的需求是集群均可生成PDF文件或是访问PDF文件，但是没有文件服务器，故做一个简易的文件服务器。

解决方案：集群内的机器（客户端）生成PDF文件之后将PDF文件推给文件服务器，我们暂且称它为服务端；如果某个客户端需要访问到这个PDF文件，则去服务端获取（因为可能其他客户端已经生成了该PDF文件），如果没有找到，则自己客户端生成PDF文件，再将PDF文件推给服务端。

为了实施简易，现采取NodeJs来实现一个小程序。不多说，直接上代码：

server.js


var express = require('express');
var url = require('url');
var fs = require('fs');
var http = require('http');
var queryString = require('querystring');
var bodyParser = require('body-parser');
var path=require('path'); 
var app = express();
app.use(bodyParser.json({limit:'1000kb'}));
app.use(bodyParser.urlencoded({limit:'1000kb',extended:true}));
var count=0;
app.post('/upload.node',function(req,resp){
 console.log('上传请求 '+ (new Date()));
 var data = new Buffer(req.body.fileData,'base64');
 var filePath = req.body.filePath;
 var pathObj = path.parse(filePath);//对文件路径字符串进行操作
 var responseBody = {};
 mkdirsSync(pathObj.dir);//递归创建文件目录
 try{
 var writerStream = fs.createWriteStream(filePath);
 writerStream.write(data); 
 writerStream.end();
 writerStream.on('finish', function() {
  console.log('上传完成 '+ (new Date()));
 });
 writerStream.on('error', function(err){
  console.log(err.stack);
 });
 responseBody=JSON.stringify({
  returnMsg:'200'
 });
 }catch(err){
 console.log('上传出错 '+ (new Date()));
 responseBody=JSON.stringify({
  returnMsg:'400'
 });
 }
 //写入文件
 //console.log('*** ' + count +' ***');
  resp.status(200).end(responseBody.toString());
});
app.post('/download.node',function(req,resp){
 console.log('下载请求 '+ (new Date()));
 var filePath = req.body.filePath;
 console.log('download');
 var responseBody = {};
 if(fs.existsSync(filePath)){
 var data = fs.readFileSync(filePath);
 var dataBase64 = data.toString('base64');
 responseBody = JSON.stringify({
  returnMsg:'200',
  filePath:filePath,
  fileData:dataBase64
 });
 console.log('下载完成 '+ (new Date()));
 }else{
 responseBody=JSON.stringify({
  returnMsg:'400'
 });
 console.log('文件未找到 '+ (new Date()));
 }
 //console.log('*** ' + ++count +' ***');
 resp.status(200).end(responseBody.toString());
});
//递归创建文件目录 同步方法
function mkdirsSync(filePath){
 if(fs.existsSync(filePath)){
 return true;
 }else{
 if(mkdirsSync(path.dirname(filePath))){
  fs.mkdirSync(filePath);
  return true;
 }
 }
}
var server = app.listen(20001,function(){
 console.log('Server started.');
})

提供一个测试js代码.. 浏览器通过get请求 http://127.0.0.1:20000/upload.do?filePath=XXXX即可触发上传过程


var express = require('express');
var url = require('url');
var fs = require('fs');
var http = require('http');
var queryString = require('querystring');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser.json({limit:'1000kb'}));
app.use(bodyParser.urlencoded({limit:'1000kb',extended:true}));
var count=0;
app.get('/upload.do',function(req,resp){
 console.log('upload.do');
 //var path = url.parse(req.url).pathname;
 //console.log('Request for ' + path);
 var filePath = req.query.filePath;
 //var fileData = req.query.fileData;
 var address = req.query.address;
 upload(filePath,'127.0.0.1',20001);
 console.log('*** ' + ++count +' ***');
 var response = {
    "first":req.query.filePath,
    "last":req.query.address
  };
  resp.end(JSON.stringify(response));
});
function upload(filePath,address,port){
 var Data = readFile(filePath);
 var dataBase64 = Data.toString('base64');
 console.log(Data);
 console.log(dataBase64);
 //var DataJSON = JSON.stringify(Data);
 //fs.writeFile('D:/input.txt',dataBase64,function(err){
 // if(err){
 // console.err(err);
 // }
 //});
 var JsonData = queryString.stringify({
 filePath:filePath,
 fileData:dataBase64
 });
 //console.log(JsonData);
 var options = {
 method: "POST",
 host : address,
 port : port,
 path : '/upload.node',
 headers: {
  'Content-Type':'application/x-www-form-urlencoded'
 }
 };
 var req = http.request(options, function(res){
  res.setEncoding('utf8');
 });
 req.write(JsonData);
 req.end();
}
function readFile(filePath){
 var fileData = '';
 try{
 fileData = fs.readFileSync(filePath);
 }catch(e){
 fileData = '';
 }
 return fileData;
}
app.post('/download.do',function(req,resp){
 //可直接参考server.js的代码
})
var server = app.listen(20000,function(){
 console.log('Server started.');
})