2021年Node.js開發人員學習路線圖

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Node.js 自發布以來，已成爲業界重要破局者之一。Uber、Medium、PayPal 和沃爾瑪等大型企業，紛紛將技術棧轉向 Node.js。Node.js 支持開發功能強大的應用，例如實時追蹤 App、視頻 \/ 文本聊天引擎、社交媒體 App 等，當前已成爲開發人員熱衷的一項技能。本文作者基於自身實施經歷，給出一張 Node.js 學習路線圖。建議開發人員考慮深入掌握 Node.js 之前，必須明確自己構建的目標，否則容易半途而廢。目標導向有助於在學習中聚焦關鍵技能，而非糾結於是否值得去學習。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"必備技能"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"JavaScript"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"對於一名前端開發人員，在考慮掌握後端技能時，無需花費大量的精力學習去 JavaScript。而對於完全小白，如果想要在儘可能短的時間內掌握 Node.js，在深入前必須領會如下概念："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"箭頭函數（Arrow 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Structures）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"this"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"循環（Loops）和作用域（Scope）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"數組對象（Arrays）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"字面量模板（Template Literals）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"嚴格模式（Strict Mode）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"ES6\/ES7"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"此外，Node.js 中涉及大量的異步編程處理，推薦掌握如下概念："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"定時器（Timers）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Promises"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"閉包（Closures）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"事件循環（Event Loop）"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"異步編程（Async programming）和回調（callbacks）"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"npm 軟件包管理"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Node 軟件包管理（Node Package Manager，npm）提供當前規模最大的註冊軟件庫，其中提供 80 多萬種軟件包。正確使用 npm，可極大地降低軟件包管理的複雜度，非常便於解決應用開發中的依賴問題。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"npm 提供三個組成模塊："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"命令行接口（Command Line Interface，CLI)：CLI 是大部分開發人員的首選方式，提供本機終端環境運行。"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"註冊軟件庫（Registry）：提供大規模開放式 JavaScript 軟件和元信息數據庫。"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Web 站點：可查找新的軟件包，並提供其它一些 npm 功能。"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"npm 還可管理各版本的代碼及依賴。如果使用 npx，無需下載軟件包即可運行軟件包。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Node.js 基礎知識"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"事件發射器（Event Emitter）"},{"type":"text","text":"：做爲 Node.js 中的對象，Event Emitter 在操作執行完成後發送消息，觸發特定的事件。開發人員也可編寫代碼，監聽 Event Emitter 發出的事件。例如，一旦完成特定的前端操作，諸如鼠標點擊、按鍵和鼠標移動等交互操作，需在後端做進一步處理。這時後端的 Node.js 環境使用 EventEmitter 類，構建相應的事件處理模塊，用於處理操作事件。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"回調"},{"type":"text","text":"（Callback）：回調是特定任務執行完成後調用的函數，不影響其它代碼的同時執行，避免了異步處理產生阻塞。鑑於 Node.js 中需處理大量的異步任務，因此回調無處不在。回調是實現應用無縫快速執行的關鍵，其運作機制如下圖所示："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/wechat\/images\/00\/00f4992880d3afd6cd61c0cde6351ab1.png","alt":null,"title":null,"style":null,"href":null,"fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Buffer 類"},{"type":"text","text":"：設計用於處理原始二進制數據的 Node.js 類，操作 V8 引擎外分配的內存。Buffer 類實現爲大小不可調整的整數數組，並提供一整套二進制數據操作方法。例如，對於表示範圍在 0 到 255 之間字節值的內存中整數，使用 console.log() 輸出該 Buffer 實例，會給出一系列十六進制值。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"模塊系統（Module System）"},{"type":"text","text":"：使用 Node.js 生態系統提供的模塊，可實現一些複雜功能。模塊是可複用的 JavaScript 代碼，實現特定的功能。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"開發技能"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"版本管理系統"},{"type":"text","text":"：掌握 git、GitHub 等的使用。開發中，應儘量避免交叉修改代碼導致的更改不可逆。因此，在大型項目中需使用版本控制系統管理。要熟悉版本控制系統的使用，開發人員應該具備紮實的基礎知識。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"HTTP\/HTTPS 協議"},{"type":"text","text":"：一位優秀的 Node.js 開發人員，應具備傳輸協議數據傳輸的基礎知識，因爲每位後端開發人員都需要深入理解 HTTP\/HTTPS 的工作機制。HTTPS 使用稱爲 TLS（Transport Layer Security）的加密協議加密通信。後端環境中有大量要學習的知識點，這對於 Web 小白是頗具難度的。簡而言之，基本的 Web 通信主要包括六種請求方法："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"GET: 獲取資源的表示；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"POST: 創建新資源；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"PUT: 更新資源；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"PATCH: 局部修改資源；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"DELETE: 刪除 URL 指定的資源"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"OPTIONS: 請求指定 URL\/ 服務器所支持的通信。"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"Web 框架"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"注意：本文僅列出了部分推薦 Web 框架。使用 Node.js 構建個人項目時，爲降低學習難度，推薦從中選定一種框架，否則學習難度很高。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Express.js"},{"type":"text","text":"：提供構建應用所需的最小化接口和工具，非常靈活易用，大量 npm 模塊可直接插入 Expresss 使用。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Meteor.js"},{"type":"text","text":"：一種構建 JavaScript 應用的萬事通框架，提供內建的 MongoDB，支持 GraphQL。運行 meteor create myapp，即可生成一個具有 MongoDB 後端的 HTML\/JavaScript 頁面。使用 Meteor.js 可有效助降低項目開發時間，並簡化項目的維護。當然如果只是構建一個簡單的 Web 應用，還是推薦使用 Express。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Sails.js"},{"type":"text","text":"：一種支持快速構建 REST API、單頁應用（SPA）和實時 APP 的 MVC 框架。如果開發人員考慮實操一些重要技能，例如使用 WebSockets 支持實時操作，使用按約定編程（convention over configuration）方法等，推薦學習 Sails.js。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Koa.js"},{"type":"text","text":"：如果開發人員考慮構建一個經得起時間考驗、易於維護的魯棒應用，Koa.js 無疑是很好的選擇。Koa 應用實現爲包含一組中間件函數數組的對象，其中函數以堆棧方式執行。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Nest.js"},{"type":"text","text":"：該框架繼承了 Angular 的理念，使用 TypeScript 構建，並且在底層使用了 Express.js，因此兼容大多數 Express 中間件。Nest 提供很好的模塊化結構，代碼組織在不同模塊中，進而構建高效、良好擴展的應用。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"數據庫管理"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"學習 Node.js 需要掌握大量的後端技能。對於一名小白，開始可選擇 MySQL 等數據庫。只有釐清後端系統設計的基礎知識，才能根據項目的需求，考慮在 MySQL 等基本 SQL 數據庫之外選取後端。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"注意：關係數據庫依然是主流。例如，在建模產品、類比、標籤等時依然主要使用關係表結構。類似於電子表格，關係表由行和列組成。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"關係數據庫管理系統"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"SQL Server"},{"type":"text","text":"：微軟的關係數據庫產品，支持標準 ANSI SQL，也提供產品獨有的 SQL 實現。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"MySQL"},{"type":"text","text":"：一款優秀的關係數據庫管理系統，時由 Oracle 提供的開源後端軟件，具備按需改進代碼的靈活性。MySQL 可很好地替代 Oracle、Microsoft SQL server 等商業數據庫產品。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"PostgreSQL"},{"type":"text","text":"：具有大規模開發團隊支持的開源產品，可運行在 Linux、UNIX 和 Windows 等大多數主流操作系統上。PostgreSQL 支持絕大多數標準 SQL 查詢，還提供複雜 SQL 查詢、外鍵、觸發器、事務、MVCC、流複製等特性。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"MariaDB"},{"type":"text","text":"：MySQL 的改進版，額外內建了多種特性、安全和性能改進。簡而言之，MariaDB 性能優於 MySQL，推薦在大型應用中使用 MariaDB。例如，MariaDB 的大型連接池支持超過 20 萬的併發連接，顯著優於 MySQL。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"雲數據庫服務"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Azure CosmosDB"},{"type":"text","text":"：一種全球分佈式數據庫服務，支持遠程管理數據。對於大型應用，雲數據庫在擴展型和可管理性上具有優勢。Microsoft Azure 完全簡化了可擴展和分佈能力，在同一後端上支持多種數據模型，即可同時用於文檔、鍵值、關係和圖模型。該服務不依賴於任何模式，因此可稱爲 NoSQL 數據庫，但可使用支持 ACID 交易的查詢語言。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"Amazon DynamoDB"},{"type":"text","text":"：非常適用於具有 SQL 經驗的用戶，提供全託管 NoSQL 數據庫服務，具有高性能，可預測，擴展性很好。DynamoDB 支持創建關係表，可存儲並檢索任何規模的數據，提供任何服務等級的請求。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"NoSQL 數據庫"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"MongoDB"},{"type":"text","text":"：面向文檔的 NoSQL 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