<Node.js入门>教程中代码的修改_node.js可以修改前端代码吗-优快云博客

本文链接：https://blog.youkuaiyun.com/imorris/article/details/9134179

本文通过一份Node.js入门教程，详细介绍了如何实现基本的文件上传功能。从代码入手，逐步解析了服务器启动、路由配置及请求处理的过程，并重点介绍了如何使用formidable模块处理文件上传。

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近日无事，准备学习一下Node.js，找到了这样的一份入门教程文档：Node.js入门

一页一页的看下来，把里面的代码也都手动的敲了一遍，最后发现并没有实现预期的效果，只能自己动手改代码了，最终实现了预期效果。

一共四个文件：

index.js

var server = require("./server");
var router = require("./router");
var handlers = require("./handlers");

var handle = {};
handle["/"] = handlers.start;
handle["/start"] = handlers.start;
handle["/upload"] = handlers.upload;
handle["/show"] = handlers.show;

server.start(router.route, handle);

server.js

var http = require("http");
var url = require("url");

function start(route, handle) {
	function onRequest(request, response) {
		var pathname = url.parse(request.url).pathname;
		console.log("Request for " + pathname + " received.");
		route(handle, pathname, response, request);
	}

	http.createServer(onRequest).listen(8888);
	console.log("Server has started.");
}

exports.start = start;

router.js

function route(handle, pathname, response, request){
  console.log("About to route a request for " + pathname);
  if (typeof handle[pathname] === 'function') {
    handle[pathname](response, request);
  } else {
    console.log("No request handler found for " + pathname);
	response.writeHead(404, {"Content-Type": "text/plain"});
    response.write("404 Not found");
    response.end();
  }
}

exports.route = route;

handlers.js

var querystring = require("querystring");
var fs = require("fs");
var formidable = require("formidable");
var util = require('util');

function start(response, request) {
  console.log("Request handler 'start' was called.");

  var body = '<html>'+
    '<head>'+
    '<meta http-equiv="Content-Type" '+
    'content="text/html; charset=UTF-8" />'+
    '</head>'+
    '<body>'+
    '<form action="/upload" enctype="multipart/form-data" '+
    'method="post">'+
    '<input type="file" name="upload">'+
    '<input type="submit" value="Upload file" />'+
    '</form>'+
    '</body>'+
    '</html>';

    response.writeHead(200, {"Content-Type": "text/html"});
    response.write(body);
    response.end();
}

function upload(response, request) {
  console.log("Request handler 'upload' was called.");
  var filePathName;
  var form = new formidable.IncomingForm();
  console.log("about to parse");
  form.uploadDir = "./tmp";  
    form
	  .on('fileBegin', function(name, file) {
		filePathName = file.path;
	  })
      .on('end', function() {
		fs.renameSync(filePathName, "./tmp/test.png");		
        	console.log('-> upload done');
		response.writeHead(200, {"Content-Type": "text/html"});
		response.write("received image:<br/>");
		response.write("<img src='/show' />");
		response.end();
      });
  form.parse(request);
}
function show(response, request) {
  console.log("Request handler 'show' was called.");
  fs.readFile("./tmp/test.png", "binary", function(error, file) {
    if(error) {
      response.writeHead(500, {"Content-Type": "text/plain"});
      response.write(error + "\n");
      response.end();
    } else {
      response.writeHead(200, {"Content-Type": "image/png"});
      response.write(file, "binary");
      response.end();
    }
  });
}

exports.start = start;
exports.upload = upload;
exports.show =  show;

主要修改的是handlers.js里upload方法，我们需要设置formidable模块上传文件的路径，文件上传成功后我们修改为我们需要的文件名即可。