从Node.js中的请求中提取POST参数

我试图通过使用-（我使用了这个，因为在这里建议-因为我如何使用express js获取发布请求？）从变量postData中的POST获取参数。

在这里-如何检索POST查询参数？

var express = require('express');
var app = express();
var fs = require('fs');
var json = require('json');
app.use(express.json());       // to support JSON-encoded bodies
app.use(express.urlencoded()); // to support URL-encoded bodies

app.post('/shrib/:file/:data',function(req,res){
    var fileName = req.params.file;
    var data = req.params.data;
    req.on('data',function(data){ body+=data; } );
    req.on('end' ,function(){
        var postData = qs.parse(body);
        var writeStream = fs.createWriteStream(fileName);
        var postData = req.body.text;
        if(postData)
            console.log(postData);
        else    
            console.log("failed miserably");
        res.write(200);
        res.end();
    });
});
app.get('/shrib/:file',function(req,res){   
    var fileName = req.params.file;
    if(fileName != ''){
        var readStream = fs.createReadStream(fileName);
        var content;
        readStream.on('data',function(chunk){
            content+=chunk.toString();
            console.log(content);
        });
        readStream.on('end',function(){
            res.writeHead(200,{"Content-Type":"text/html"});
            res.write("<form id=\"submitForm\" method=\"POST\">");
            res.write("<textarea id=\"text\"rows=50 cols=50 >");
            console.log(content);
            if(content)
                res.write(content.toString());
            res.write("</textarea>");
            res.write("<input type=\"submit\" value=\"submit\" />");
            res.write("</form>");
            res.write("<script>");
            res.write("var windowLocation = location.href;");
            res.write("document.getElementById(\"submitForm\").action=windowLocation + \'/data\';");
            res.write("</script>");
            res.end();
        });
    }else{
        res.writeHead(200);
        res.write("invalid/empty path name"); 
    }
});
app.listen(8080);

并收到此错误-

Error: Most middleware (like json) is no longer bundled with Express and must be installed separately. Please see https://github.com/senchalabs/connect#middleware.
    at Function.Object.defineProperty.get (/home/unknown/public_html/node/node_modules/express/lib/express.js:89:13)

我使用的是body解析器，在此之前我在这里阅读了一些解决方案，它给了我相同的错误中间件，我在全局安装了它，然后也遇到了同样的错误，然后我读到了有关json的信息，所以我使用了

npm install -g json

没用，那也是。然后我尝试添加依赖项-

{
  "name": "express_shrib.js",
  "version": "0.0.1",
  "description": "Creating Shrib Using Express",
  "main": "express_shrib.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/iamdeadman/nodejs.git"
  },
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/iamdeadman/nodejs/issues"
  },
  "homepage": "https://github.com/iamdeadman/nodejs",
  "dependencies": {
    "express": ">= 1.2.0",
    "json": ">= 9.0.0"
  }
}

并运行npm install仍然相同的错误-

Error: Most middleware (like json) is no longer bundled with Express and must be installed separately. Please see https://github.com/senchalabs/connect#middleware.
    at Function.Object.defineProperty.get (/home/unknown/public_html/node/node_modules/express/lib/express.js:89:13)

编辑**-使用新的body-parser模块进行编码

var express = require('express');
var app = express();
var fs = require('fs');
var bodyParser = require('body-parser');
app.use(bodyParser());
app.post('/shrib/:file/:data',function(req,res){
    var fileName = req.params.file;
    var data = req.params.data;
    req.on('data',function(data){ body+=data; } );
    req.on('end' ,function(){
        var postData = req.body;
        var writeStream = fs.createWriteStream(fileName);
        if(postData)
            console.log(postData);
        else{   
            console.log("failed miserably");
            console.log(postData);
        }
        res.writeHead(200);
        res.end();
    });
});
app.get('/shrib/:file',function(req,res){   
    var fileName = req.params.file;
    if(fileName != ''){
        var readStream = fs.createReadStream(fileName);
        var content;
        readStream.on('data',function(chunk){
            content+=chunk.toString();
            console.log(content);
        });
        readStream.on('end',function(){
            res.writeHead(200,{"Content-Type":"text/html"});
            res.write("<form id=\"submitForm\" method=\"POST\">");
            res.write("<textarea id=\"text\"rows=50 cols=50 >");
            console.log(content);
            if(content)
                res.write(content.toString());
            res.write("</textarea>");
            res.write("<input type=\"submit\" value=\"submit\" />");
            res.write("</form>");
            res.write("<script>");
            res.write("var windowLocation = location.href;");
            res.write("document.getElementById(\"submitForm\").action=windowLocation + \'/data\';");
            res.write("</script>");
            res.end();
        });
    }else{
        res.writeHead(200);
        res.write("invalid/empty path name"); 
    }
});
app.listen(8080);

在这里我得到

{}

在控制台中，这意味着主体对象出于某种原因为空。