如何在Java中使用Scanner類及其next（）方法？

Question

您好我有這樣的Java代碼，

import java.io.*; 
import java.util.*; 
public class SongWriter 
{ 
    public static void main(String[] args) 
    { 
    PrintWriter outputStream = null; // Scope must be outside the try/catch structure 
    try 
    { 
     outputStream = new PrintWriter("Song.txt"); // new 
     FileOutputStream("Song.txt") 
    } 
    catch(FileNotFoundException e) 
    { 
     System.out.println("Error opening the file Song.txt."); 
     System.exit(0); 
    } 
    System.out.println("\n classical songs has many lines"); 
    System.out.println("\nNow enter the three lines of your Song."); 
    String line = null; 
    Scanner keyboard = new Scanner(System.in); 
    int count; 
    for (count = 1; count <= 3; count++) 
    { 
     System.out.println("\nEnter line " + count + ": "); 
     line = keyboard.nextLine(); 
     outputStream.println(count + "\t" + line); 
    } 
    outputStream.close(); 
    System.out.println("\nYour Song has been written to the file Song.txt.\n"); 
    } // end of main 
} // end of class 

如何調整的程序，所以它首先要求寫入文件的名稱。使用Scanner類和它的next（）方法。在通知讀者文件名應以後綴.txt 告終後，請在文件名中作爲字符串變量讀取。例如： - 文件名爲Haiku1.txt，Haiku2.txt和Haiku3.txt的歌曲。

Answer 1

你差點沒錢了。

Scanner keyboard = new Scanner(System.in); 
System.out.println("Enter first file name:"); 
String first = keyboard.nextLine(); 
System.out.println("Enter second file name:"); 
String second = keyboard.nextLine(); 
System.out.println("Enter third file name:"); 
String third = keyboard.nextLine(); 
//and so on and continue whatever you want to do.. 

編輯：在您的評論後。

首先將這3行存儲在StringBuilder中，然後詢問要寫入的文件名。現在你有歌詞和文件名。

Answer 2

使用掃描儀類從用戶那裏得到輸入：

String fileName1; 
Scanner keyboard = new Scanner(System.in); //creates Scanner object 
System.out.print ("Enter the name of the file. The file should end in the suffix .txt") //prompt the user to enter the file name 
fileName1 = keyboard.next(); //store the name of the file 

你應該在try/catch塊之前這樣做，這樣你可以使用用戶輸入的，而不是硬編碼（像你這樣的文件名這裏用song.txt）。

您可以用這種方式提示用戶輸入儘可能多的文件名稱。