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Thread: PrintStream Help!

  1. #1
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    Lightbulb PrintStream Help!

    I want to create a simple console account application that allow's you to create accounts and the accounts will be save in a txt files. Code:
    package main;
     
    import static java.lang.System.out;
     
    import java.io.File;
    import java.io.FileNotFoundException;
    import java.util.Scanner;
     
    public class mainClass {
     
            public static void main(String[] args) throws FileNotFoundException {
                    Scanner sn = new Scanner(new File("Usernames.txt"));
                    Scanner s = new Scanner(System.in);
                    newAccount a = new newAccount();
                    int ID = 0;
     
                    while(sn.hasNext()){
                            ID = ID + 1;
                            sn.nextLine();
                    }
                    do{
            out.print("Enter username: ");
            a.user = s.nextLine();
            out.print("Enter password: ");
            a.password = s.nextLine();
            a.ID = ID;
            a.print();
            out.println();
            out.print("Create another account?");
                    }while(s.findWithinHorizon(".", 0).charAt(0) == 'y');
     
            }
     
    }
     
    //Method class
     
    package main;
     
    import java.io.FileNotFoundException;
    import java.io.PrintStream;
     
    public class newAccount {
     
            String user;
            String password;
            int ID;
     
            void print() throws FileNotFoundException{
     
                PrintStream u = new PrintStream("Usernames.txt");
                    PrintStream p = new PrintStream("Passwords.txt");
     
     
                    for(int i = 0; i < ID; i++){
                            p.println();
                            u.println();
                    }
            u.println(user);
            p.println(password);
            }
    }
    My problem: Every time a new account is created all previous accounts will be deleted because I use: u.println(""); and p.println(""); How can I fix this problem? Thanks!
    Last edited by Norm; June 22nd, 2014 at 11:53 AM. Reason: change quote to code tags


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: PrintStream Help!

    Please post the code here that you are having problems with.

    Is this the problem: when adding a new record to an existing file, the old file is overwritten instead of the new record added to the end?
    Look at using the file writing class's constructor with the append option.
    If you don't understand my answer, don't ignore it, ask a question.

  3. The Following User Says Thank You to Norm For This Useful Post:

    DayzZombie (June 22nd, 2014)

  4. #3
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    Default Re: PrintStream Help!

    Yes that is the problem, and can you give me an example of the file append option? Thanks for the reply!

  5. #4
    Super Moderator Norm's Avatar
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    Default Re: PrintStream Help!

    Use the class that has the append option in the class's constructor. Set it to true.
    I don't know the name of the class right now. It might be FileWriter. Look in the API doc.
    If you don't understand my answer, don't ignore it, ask a question.

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