我使用為我的學(xué)校作業(yè)提供的唯一用戶名創(chuàng)建了一個(gè)基本的登錄和注銷(xiāo)系統(tǒng)（無(wú)數(shù)據(jù)庫(kù)），但我在 while 循環(huán)和會(huì)話時(shí)間方面遇到了問(wèn)題。我嘗試將一組代碼復(fù)制并粘貼到此主代碼的不同部分，以便獲得預(yù)期的結(jié)果，但結(jié)果有點(diǎn)錯(cuò)誤。我試圖在互聯(lián)網(wǎng)上搜索有關(guān)會(huì)話時(shí)間的信息，但一無(wú)所獲。  while (login =  true){      try {          System.out.println("Enter your name:");          String name = cue.nextLine();          System.out.println("--------------------");          System.out.println("");          System.out.println("Date and Time of Login:");          System.out.println(dtf.format(now));          System.out.println("");          System.out.println("--------------------");          System.out.println();          System.out.println("Enter your name to log out:");          String logout = cue.nextLine();          System.out.println("");          if (logout.equals(name)){              System.out.println("--------------------");              System.out.println("");              System.out.println("Date and Time of Logout:");              System.out.println(dtf.format(now));              System.out.println("Session Time:");              /*can you also please tell me what code to tell the gap between the               login time and log out time?*/              System.out.println("");              System.out.println("--------------------");              login = false;            } else {                login = true;            }        } catch (Exception e){          cue.nextLine();      } finally{          System.out.println("Do you want to register again? 0 for yes and 1 for no");          int no = cue.nextInt();          if (no==0) {              login = true;          } else if (no==1) {                System.exit(1);          } else {              System.out.println("1 or 0 only!");          }         }}這必須是預(yù)期的輸出：如果名稱(chēng)正確：Enter your name:nmae--------------------Date and Time of login:2019/02/03 16:38:46--------------------Enter your name to log out:nmae--------------------