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  1. #1
    beauti477 is offline Member
    Join Date
    Jul 2011
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    Default Trying to write to a file but it only prints last line

    I used the PrintWriter fout and it creates the new file secret.txt but it only writes the last line, why could this be, am I missing something?
    Java Code:
    public class NsaEncoder	 
      public static void main(String[] argv) throws Exception 
        BufferedReader fin;
        BufferedReader cin;
        cin = new BufferedReader(new InputStreamReader(;
        // open a file whose name is entered by the user 
        String fileName; 
        System.out.println("What file do you want to use for input? "); 
        fileName = cin.readLine(); 
        fin = new BufferedReader(new FileReader(fileName));
        while (true) 
          if (!fin.ready()) break; 
          String lineFromFile;
          lineFromFile = fin.readLine();
          String sNew = ""; 
          for (int i = 0; i < lineFromFile.length(); i++)
          sNew += (char)(lineFromFile.charAt(i) + 1); 
          PrintWriter fout;
          fout = new PrintWriter(new FileWriter("secret.txt"));
        } // while 
      // main 
    } // public class

  2. #2
    sunde887's Avatar
    sunde887 is offline Moderator
    Join Date
    Jan 2011
    Richmond, Virginia
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    Your printwriter is initialized in the loop each time. This is going to write over the first line each time through the loop. It's also terribly slow if you solve the bug. The print writer should be initialized outside of loops and open the file only once, then write to the file until you are done with it. Finally, you close it.

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