CODEWITHSUNDEEP
javaswinguser-interface
AHMED ALI
AHMED ALI

Reputation: 27

Java GUI Search Word From File Then Continue

I have a GUI for user login.

First the user creates his account, and that information is stored in a .txt file. I use PrintWriter to append details in that file. The details are stored using a separator. I can easily read every detail of a user from the file.

In the login UI, I have 2 JTtextField components in a JFrame the first one for the user name and the second onw for the password.

I get the values using the getText method:

String user = user.getText();
String password = password.getText();

I tried using BufferedReader but I can't get it to work:

if(user.equals(br.readline))

What i want to do is scan the file and if anything in the file is equal to the username (The getText from user on Frame) then I want to use SetVisible to go to Next Frame

My problem is that even on wrong password and user it go to new frame

How can I fix that?

Code to Check for User and Password, found online on StackOverflow still now working.

Scanner sc = new Scanner(new File("Details.txt"));
while(sc.hasNextLine()) {
    int val =0;
    String line = sc.nextLine();
    if(line.indexOf(user)   !=-1   && line.indexOf(pass)   !=-1) {
        JOptionPane.showMessageDialog(null,"Login");
        val = 1;
        vf.setVisible(true);
        break;
    } else {
        JOptionPane.showMessageDialog(null,"Invalid");
        val = 0;
        break;
    }
}

Another Code which is used in for , while even in do while loop , still not working.

File file  = new File("Details.txt");
BufferedReader br = new BufferedReader(new FileReader("Details.txt"));
String Line;      

do{
    if(user.equals(br.readLine()) && pass.equals(br.readLine())){
        vf.setVisible(true);
    } else {
        JOptionPane.showMessageDialog(null,"Invalid");
    }
}while((Line=br.readLine())  !=null )

This is how Users Details are Stored in My File.

=======================  
=======================  

 First Name = Ahmed Ali 
 Last Name = Qazi
 Address = Al-Abbass Colony pHase 2
 Phone Number = +92032329301
 Email Address = [email protected]
 UserName = ahmedfirst67
 Password = dangerd = 2hg

=======================  
=======================  







=======================  
=======================  

 First Name = Ahm345 
 Last Name = Qa345
 Address = Al-asfafs
 Phone Number = +92032329301
 Email Address = ahmgsdg
 UserName = ahmegg
 Password = dagg

Upvotes: 0

Views: 278

Answers (1)

Bentaye
Bentaye

Reputation: 9756

It is not straightforward given your file structure but you can do it this way:

  • Scan the file until you find the username.
  • Once you found the user name, keep scanning until you reach the password line.
  • Read this password and exit the scanning loop.
  • Then compare the given password with the one you found in the file.

Here is the code:

private static boolean checkCredentials(String user, String pass) throws IOException {

    Scanner sc = new Scanner(new File("Details.txt"));

    boolean userFound = false;
    String correctPassword = null;

    String line;
    while(sc.hasNextLine()) {
        line = sc.nextLine();
        // find the user
        if(!userFound) {
            userFound = line.contains("UserName = "+user);
        } else {
            // find the password
            if(line.contains("Password = ")) {
                correctPassword = line.substring(line.indexOf("=") + 2);
                break;
            }
        }
    }

    return correctPassword!=null && correctPassword.equals(pass);
}


public static void main(String[] args) throws IOException {
    System.out.println(checkCredentials("Bob", "dagg"));
    System.out.println(checkCredentials("ahmegg", "daggy"));
    System.out.println(checkCredentials("ahmegg", "dagg"));
}

This prints:

false
false
true

Stick it in your code like this:

val = 0;
String message = "Invalid";
if(checkCredentials(user, pass)) {
    message = "Login";
    val = 1;
    vf.setVisible(true);
}
JOptionPane.showMessageDialog(null, message);

NOTE:

It would be lot easier if you stored the details on one line this way:

Ahmed Ali|Qazi|Al-Abbass Colony pHase 2|+92032329301|[email protected]|ahmedfirst67|dangerd = 2hg
Ahm345|Qa345|Al-asfafs|+92032329301|ahmgsdg|ahmegg|dagg

You could use the String.split method to parse each line and get user and password at the same time.

NOTE 2:

Also it is very bad practice to store password unencrypted. If this is a school exercise it is fine, but if it is for a real life project, you might want to look at encrypting the passwords in the file.

Upvotes: 1

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