Node.js模块化-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_40884528/article/details/111077036

Node入门模块化

参考：https://www.nodebeginner.org/index-zh-cn.html

1. 处理post请求（提交表单）

目录结构

index.js

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

// 请求处理程序的集合
var handle = {}
handle["/"] = requestHandlers.start;
handle["/start"] = requestHandlers.start;
handle["/upload"] = requestHandlers.upload;
server.start(router.route, handle);

server.js

// 引入http模块
var http = require("http");
var url = require("url");
function start(route, handle) {
  http.createServer(function(request, response) {
    // 浏览器都会在你访问 http://localhost:8888/ 时尝试读取 http://localhost:8888/favicon.ico
    var pathname = url.parse(request.url).pathname;
    console.log("收到 " + pathname + " 请求。");

    // 为了整个过程非阻塞，Node.js会将POST数据拆分成很多小的数据块
    // 通过触发特定的事件将这些小数据块传递给回调函数
    // data事件表示新的小数据块到达了
    // end事件表示所有数据都已经接收完毕
    var postData = "";
    request.setEncoding("utf-8");
    request.addListener("data", function(postDataChunk) {
      postData += postDataChunk;
      console.log("接收的POST数据块：" + postDataChunk);
    })

    request.addListener("end", function() {
      route(handle, pathname, response, postData);
    })
    
    // response.writeHead(200, {"Content-Type": "text/plain"});
    // response.write("Hello World");
    // response.end();
  }).listen(8888);
  
  console.log("服务器已启动。");
}
exports.start = start;

router.js

function route(handle, pathname, response, postData) {
  console.log("将传送的请求是：" + pathname);
  if(typeof handle[pathname] === 'function') {
    handle[pathname](response, postData);
  } else {
    console.log("找不到的请求处理程序：" + pathname);
    response.writeHead(404, {"Content-Type": "text/html"});
    response.write("404 Not Found");
    response.end();
  }
}
exports.route = route;

requestHandlers.js

var querystring = require("querystring");
function start(response, postData) {
  console.log("已调用请求处理程序“start”。");
  var body = '<html>'+
  '<head>'+
    '<meta http-equiv="Content-Type" content="text/html;charset=UTF-8"/>'+
  '</head>'+
  '<body>'+
    '<form action="/upload" method="post">'+
      '<textarea name="text" rows="20" cols="60"></textarea>'+
      '<input type="submit" value="Submit text" />'+
    '</form>'+
  '</body>'+
'</html>';
  
  response.writeHead(200, {"Content-Type": "text/html"});
  response.write(body);
  response.end();
}

function upload(response, postData) {
  console.log("已调用请求处理程序“upload”。");
  response.writeHead(200, {"Content-Type": "text/plain"});
  // response.write("You've sent: " + postData); // text=postData
  response.write("You've sent: " + querystring.parse(postData).text);
  response.end();
}

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

2. 上传图片并显示

首先导入模块：npm install formidable

目录结构

index.js

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

// 请求处理程序的集合
var handle = {}
handle["/"] = requestHandlers.start;
handle["/start"] = requestHandlers.start;
handle["/upload"] = requestHandlers.upload;
handle["/show"] = requestHandlers.show;

server.start(router.route, handle);

server.js

// 引入http模块
var http = require("http");
var url = require("url");
function start(route, handle) {
  http.createServer(function(request, response) {
    var pathname = url.parse(request.url).pathname;
    console.log("收到 " + pathname + " 请求。");
    route(handle, pathname, response, request);
  }).listen(8888);
  console.log("服务器已启动。");
}
exports.start = start;

router.js

function route(handle, pathname, response, request) {
  console.log("将传送的请求是：" + pathname);
  if(typeof handle[pathname] === 'function') {
    handle[pathname](response, request);
  } else {
    console.log("找不到的请求处理程序：" + pathname);
    response.writeHead(404, {"Content-Type": "text/html"});
    response.write("404 Not Found");
    response.end();
  }
}
exports.route = route;

requestHandlers.js

var fs = require("fs");
var formidable = require("formidable");

function start(response) {
  console.log("已调用请求处理程序“start”。");
  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("已调用请求处理程序“upload”。");

  var form = new formidable.IncomingForm();
  console.log("即将解析");
  form.parse(request, function(error, fields, files) {
    console.log("解析完毕");
    fs.renameSync(files.upload.path, "./tmp/test.png", function(err) {
      if(err) {
        fs.unlink("/tmp/test.png");
        fs.rename(files.upload.path, "./tmp/test.png");
      }
    });
    response.writeHead(200, {"Content-Type": "text/html"});
    response.write("received image:<br/>");
    response.write("<img src='/show' />");
    response.end();
  })
}

function show(response) {
  console.log("已调用请求处理程序“show”。");
  response.writeHead(200, {"Content-Type": "image/png"});
  fs.createReadStream("./tmp/test.png").pipe(response);
  // 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;