使用node.js读取文件

Question

尝试使用node.js

读取文件

    var fs = require('fs');
    fs.readFile("details.txt",'utf8',function(err,data)
    {
        if(err)
        {
            return console.log(err);
        }
        response.write(data);
    });

在同一目录中有一个文件alredy和一些文本。

我得到的错误是：

回复于（数据）;                ^ ReferenceError：未定义数据

Answer 1

上面的img显示了我的文件顺序。注意：我使用的是IntelliJ IDEA。你必须找到文件＆＃34; details.txt＆＃34;在你的系统中。

//Instead of using hard coded path, use: the following code to get the path in Node.js
//var path = require('path');
//console.log(path.join(__dirname, '../details.txt'));

//require file system
var fs = require('fs');

//read file
fs.readFile("details.txt",'utf8',function(err,data){

  //if error, log error and return
  if(err) { return console.error('Error: ' + err); }


  //check if there is data in the file
  if(data) {

     //EDITED to include line break
    //write response
    //response.write('<div style="color:green">' + data + '</div>');

    //write response with <br>
    response.write('<div style="color:green">' + data.split('\n').join('<br>') + '</div>');

    //end the response
    response.end();


  //if no data on the file, do the following
  }else{
    //error variable
    var error = "Error: file is empty: " + data.length + " bytes.";

    //log error
    // console.error(error);

    //write response
    response.write('<div style="color:red">' + error + '</div>');

    //end response
    response.end();
  }
});

Answer 2

尝试使用完整路径＆＃39; details.txt＆＃39; （即＆＃39; / etc / hosts＆＃39;）。并将其发送到console.log以确认它是否有效。

Answer 3

   var fs = require('fs');
    fs.readFile("details.txt",'utf8',function(err,data)
    {
        if(err)
        {
            return console.log(err);
        }
        console.log(data);
    });

错误是

response.write(data)