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Using HTTP cookies 閱讀 資料來源︰ https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies An  HTTP cookie  (web cookie, browser cookie) is a small piece of data that a server sends to the user's web browser. The browser may store it and send it back with later requests to the same server.  Typically, it's used to tell if two requests came from the same browser — keeping a user logged-in, for example. It remembers stateful information for the  stateless  HTTP protocol. http cookie是從server端發送到user端的瀏覽器的一小段data。瀏覽器會儲存它並將它和以後的requests一起發送回同一的server端。一般來說，它是被用來判斷兩個requests是否來自同一個瀏覽器---保持用戶登入狀。舉例來說，他在stateless http protocol 記住 stateful information。 Cookie主要有3個目的︰ Session management 通訊管理     Logins, shopping carts, game scores, or anything else the server should remember Personalization 個性化     User preferences, themes, and other settings Tracking 追蹤     Recording and analyzing user behavior 記錄與分析用戶行為 Creating cookies After receiving an HTTP

ETL ETL = Extract-Transform-Loading 過程 Raw Data -> ETL Script -> Tidy Data (結構化資料) Java FileReader  把檔案裡的字元讀進來以後呢，轉換成看得懂的文字。 FileReader fReader = new FileReader ("filename") BufferedReader 為所接受到的內容建立一個緩衝的功能。 bReader = new BufferedReader(fReader); e.g. BufferedReader bReader = null; String line; FileReader fReader; fReader = new FileReader("filename.txt"); bReader = new BufferedReader(fReader); while((line= bReader.readLine()) != null){          System.out.println(line); } ***為什麼要有BufferedReader？(用BufferReader接載FileReader) 因為如果資料量很大的話，主記憶體又有限，一次讀進來的話 會用掉很多記憶體，所有BufferedReader可以針對Buffer進行 資料段的讀取、修改與刪除。 Scanner Scanner 可以使用正規表達式(Regular Expression) 剖析(Parsing)基本資料型態與字串 Scanner sc = new Scanner (new File("FileName")); while(sc.hasNextLine()){     String next = sc.nextLine(); }