如何在運行Node.js的服務器上保存文件？

Question

我有一臺運行Node.js的服務器。我必須從html頁面（「index.html」）讀取表單數據並將該數據寫入txt文件。

這是我的index.html：

<form action="/uploads" method="post"> 
    <table> 
     <tr> 
     <td><img src="images/ktulogo.png" width="100" height="100"></td> 
     <td> 
      <h3>Karadeniz Teknik Üniversitesi Bilgisayar Mühendisliği Bölümü</h3> 
     </td> 
     </tr> 
     <tr> 
     <td><br></td> 
     <td> 
      <hr> 
     </td> 
     </tr> 
     <tr> 
     <td> 
      <h4>Adınız Soyadınız :</h4> 
     </td> 
     <td><input type="text" style="margin-left: 5%; width: 40%"></td> 
     </tr> 
     <tr> 
     <td> 
      <h4>Öğrenci Numaranız :</h4> 
     </td> 
     <td><input name="ogrNo" type="text" style="margin-left: 5%; width: 40%"></td> 
     </tr> 
     <tr> 
     <td> 
      <h4>Cevabınız :</h4> 
     </td> 
     <td><textarea name="answer" datatype="text" rows="10" cols="100" style="margin-left: 5%; resize: none"></textarea></td> 
     </tr> 
    </table> 
    </br> 
    <center> 
     <button id="saveFile" class="btn btn-success" style="width: 30%">Sisteme Yükle</button> 
    </center> 
</form> 

這裏是我的app.js：

var express = require('express'); 
var app = express(); 
var path = require('path'); 
var fs = require('fs'); 

app.use(express.static(path.join(__dirname, 'public'))); 

app.get('/', function(req, res){ 
    res.sendFile(path.join(__dirname, 'views/index.html')); 
}); 

app.post('/uploads', function (req, res) { 
    var file_name = req.body.ogrNo; 
    var file_content = req.body.answer; 
    file_content = file_content.replace(/\n/g, "\r\n"); 

    var stream = fs.createWriteStream(file_name+".txt"); 
    stream.once('open', function() { 
     stream.write(file_content); 
     stream.end(); 
    }); 
}); 

var server = app.listen(3000, function(){ 
    console.log('Server listening on port 3000'); 
}); 

當我運行它，它會引發我一個錯誤：

TypeError: Cannot read property 'ogrNo' of undefined at c:\Users\Volkan\IdeaProjects\File Upload\app.js:13:27 at Layer.handle [as handle_request] (c:\Users\Volkan\IdeaProjects\File Upload\node_modules\express\lib\router\layer.js:95:5) at next (c:\Users\Volkan\IdeaProjects\File Upload\node_modules\express\lib\router\route.js:131:13) at Route.dispatch (c:\Users\Volkan\IdeaProjects\File Upload\node_modules\express\lib\router\route.js:112:3) at Layer.handle [as handle_request] (c:\Users\Volkan\IdeaProjects\File Upload\node_modules\express\lib\router\layer.js:95:5) at c:\Users\Volkan\IdeaProjects\File Upload\node_modules\express\lib\router\index.js:277:22 at Function.process_params (c:\Users\Volkan\IdeaProjects\File Upload\node_modules\express\lib\router\index.js:330:12) at next (c:\Users\Volkan\IdeaProjects\File Upload\node_modules\express\lib\router\index.js:271:10) at serveStatic (c:\Users\Volkan\IdeaProjects\File Upload\node_modules\serve-static\index.js:75:16) at Layer.handle [as handle_request] (c:\Users\Volkan\IdeaProjects\File Upload\node_modules\express\lib\router\layer.js:95:5)

那麼，我的問題的原因是什麼，或者我該如何處理這項工作？

Answer 1

你必須分析傳入的數據，爲此目的使用body-parser

首先安裝

npm i -S body-parser 

然後導入到你的代碼

var bodyParser = require('body-parser') 

添加解析器

// parse application/x-www-form-urlencoded 
app.use(bodyParser.urlencoded({ extended: true })); 

// parse application/json 
app.use(bodyParser.json()); 

就是這樣。