java流關閉錯誤

Question

我正在寫一個簡單的程序，使用Vigenere密碼對文本文件中的文本進行加密和解密。該大綱代碼粘貼下面

import java.io.*; 
public class VigenereCipher 
{ 
    public static void main(String [] args) 
    throws IOException 
    { 
     char [][] cipherKey = new char[26][26]; 
     String fileName, keyword; 
     System.out.println("Enter the file Name to Read"); 
     BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
     fileName = br.readLine(); 
     System.out.println("Enter the Keyword"); 
     keyword = br.readLine(); 
     keyword = keyword.toUpperCase(); 
      br.close(); 
     //to read the file line by line and convert 
     br = new BufferedReader(new FileReader(fileName)); 
     while((line = br.readLine()) != null){ 
      line = line.toUpperCase(); 
      //More code to perform the substitution, removed to reduce the code 
     } 
     br.close(); 
     //code for decryption 
     System.out.println("Enter the filename to decode"); 
       try 
       { 
     BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in)); 
     fileName = br1.readLine(); 
       br1.close(); 
       }catch(Exception ex){ System.out.println(ex.getMessage());} 
       System.out.println(fileName); 
     br = new BufferedReader(new FileReader(fileName)); 
     while((line = br.readLine()) != null){ 
      line = line.toUpperCase(); 
      //The decryption code is here 
     } 
      br.close(); 
    } 
} 

我從try catch塊

Stream closed 

我不明白，在System.in流可以如何被關閉下面的消息？ 我犯了什麼錯誤，我該如何解決？

Answer 1

，因爲你看了在文件名後與第一

br.close(); 

你發出關閉它的流被關閉。

不要關閉該閱讀器，也不要爲System.in創建一個新的閱讀器 - 只需重新使用該閱讀器即可。儘管如此，使用不同的閱讀文件。