How to Create Login and Register Form in Java NetBeans with Text File

Java Login And Register Form With Text File

In this Java Long Tutorial we will go step by step on How To Design a Login And Register Form, plus how to use those two form with a text file so the user can signup and signin.

What We Are Gonna Use In This Project:

- Java Programming Language.
- NetBeans Editor.
- Text File.

What We Will Do In This Project:

- Design One Form For The Login and Signup Using JPanels and Borders.
- Add an Icon Using JLabels To Close The Form.
- add Data into the text File When User Register.

- Allow The User to Login.
- Check If The User Leave Some Fields Empty.
- Check If The User Enter Username That Already Exists.
- Check If The User Enter a Wrong Password In The Confirmation Field.

- Create a Message orm To Display When An Error Occure or To Display Any Information.

- Create a Main Form to Display After The User Login.

Project Source Code:

// create a border for the jpanel

Border panel_border = BorderFactory.createMatteBorder(2, 2, 2, 2, Color.gray);

// create a border for the textfields

Border textfields_border = BorderFactory.createMatteBorder(0, 0, 2, 0, Color.white);

// optional red border

Border textfields_red_border = BorderFactory.createMatteBorder(0, 0, 2, 0, Color.red);

// create a border for the jlabels

Border lbl_border = BorderFactory.createMatteBorder(0, 0, 2, 0, Color.lightGray);

// the file path -> C:\Users\1BestCsharp\Desktop\java_app

String usersFilePath = "C:\\Users\\1BestCsharp\\Desktop\\java_app\\users.txt";

// array of all usernames

ArrayList<String> all_usernames = new ArrayList<>();

// a hashmap of usernames and password

Map<String, String> usernameANDpassword = new HashMap<>();

// the message frame

Message_Frame msgF = new Message_Frame();

public Login_And_Register() {

initComponents();

// image link: https://pixabay.com/vectors/cross-no-x-forbidden-closed-42928/

// display close images in jlabel

displayImage();

// center the form

this.setLocationRelativeTo(null);

// set borders

jPanel_main.setBorder(panel_border);

jLabel_login_title.setBorder(lbl_border);

jLabel_register_title.setBorder(lbl_border);

jTextField_login_username.setBorder(textfields_border);

jPasswordField_login_pass.setBorder(textfields_border);

jTextField_register_username.setBorder(textfields_border);

jTextField_register_fullname.setBorder(textfields_border);

jTextField_register_email.setBorder(textfields_border);

jPasswordField_register_pass.setBorder(textfields_border);

jPasswordField_register_confirmPass.setBorder(textfields_border);

getUsers();

// test

for(String uname:all_usernames)

{

System.out.println(uname);

}

// create a function to get all users

public void getUsers()

{

// the info structure will be like this

Username: aaa

Fullname: bbb ccc

Email: abc@mail.com

Password: pass123

---

File file = new File(usersFilePath);

String username = "";

String password = "";

try {

FileReader fr = new FileReader(file);

BufferedReader br = new BufferedReader(fr);

// read line by line from the text file

Object[] lines = br.lines().toArray();

for(int i = 0; i < lines.length; i++)

{

// splite the row into two rows

// one for the name of the field

// and the other for the value of the field

String[] row = lines[i].toString().split(": ");

if(row[0].equals("Username"))

{

// if it's the username field we will get the username

username = row[1];

// add the username to the all username array

all_usernames.add(username);

}

else if(row[0].equals("Password"))

{

// if it's the password field we will get the password

password = row[1];

}

if(!username.equals("") && !password.equals(""))

{

// add the username and the password to the hashmap

usernameANDpassword.put(username, password);

}

} catch (FileNotFoundException ex) {

Logger.getLogger(Login_And_Register.class.getName()).log(Level.SEVERE, null, ex);

}

// create a function to check if the username already exist

public boolean checkIfUsernameExist(String un)

{

boolean exist = false;

for(String username: all_usernames)

{

if(username.equals(un))

{

exist = true;

}

return exist;

}

// function to display image

public void displayImage()

{

ImageIcon imgico = new ImageIcon(getClass().getResource("\\/images/x.png"));

Image img = imgico.getImage().getScaledInstance(jLabel_close_.getWidth(), jLabel_close_.getHeight(), Image.SCALE_SMOOTH);

jLabel_close_.setIcon(new ImageIcon(img));

}

private void jLabel_close_MouseClicked(java.awt.event.MouseEvent evt) {

// close the form

this.dispose();

}

private void jButton_register_ActionPerformed(java.awt.event.ActionEvent evt) {

// get the textfields data

String username = jTextField_register_username.getText().trim();

String fullname = jTextField_register_fullname.getText().trim();

String email = jTextField_register_email.getText().trim();

String password = String.valueOf(jPasswordField_register_pass.getPassword()).trim();

String confirm_password = String.valueOf(jPasswordField_register_confirmPass.getPassword()).trim();

File file = new File(usersFilePath);

try {

// file = the file we want to write on

// true = we wan to append the text on it

FileWriter fw = new FileWriter(file, true);

// we need to check if the textfields are empty

// we need to check if the confirmation password equal the password

// we need to check if the username already exist

// check if the textfields are empty

if( username.equals("") || fullname.equals("") || email.equals("") || password.equals("") )

{

System.out.println("One Or More Fields Are Empty");

msgF.jLabel_Title.setText("Signup Error");

msgF.jLabel_message.setText("One Or More Fields Are Empty");

}

else{

// confirmation password

if(password.equals(confirm_password))

{

// check if the username already exist

if(!checkIfUsernameExist(username))

{

fw.write("Username: " + username);