I’m having trouble with my code. the logic of my code is, when it doesn’t find the username I entered a confirmation box will appear, what really happen is when a entered username is found in a line
it doesn’t launched the confirmation box “that’s alright” but it continue searching throughout every line and initialize else {statement} btw, my else statement is the confirmation box.
a sample data.dat that my code writes
shawn | qwerty1234
cloe | password1234
jones | shittybrix
When I entered “shawn” it launches my if statement “that’s alright”
but it continues searching throughout the string and the entered Username “shawn” became not equal to cloe and jones, it launches the else statement giving me two confirmation box respectively.
I want to avoid that error but I don’t know how.
THE ERROR OCCURS IN REGISTER.JAVA
this is my code for login:
package login;
import java.awt.HeadlessException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import javax.swing.JOptionPane;
public class Login extends javax.swing.JFrame {
public Login() {
initComponents0();
}
@SuppressWarnings("unchecked")
private void initComponents0() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
uname = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
login = new javax.swing.JButton();
reset = new javax.swing.JButton();
pwd = new javax.swing.JPasswordField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N
jLabel1.setText("Login Pane");
jLabel2.setText("User Name:");
jLabel3.setText("Password:");
login.setText("Login");
login.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
String un = uname.getText();
try {
try (BufferedReader br = new BufferedReader(new Filereader("data.dat"))) {
String strLine;
while ((strLine = br.readLine()) != null) {
if (strLine.startsWith(un)) {
JOptionPane.showMessageDialog(null, "Hello: " + un, "Registration", JOptionPane.INFORMATION_MESSAGE);
} else {
int sel = JOptionPane.showConfirmDialog(null, "It seems that you haven't registered yet? \n Lunch Registration Pane?", "Admin", JOptionPane.INFORMATION_MESSAGE);
if (sel == JOptionPane.YES_OPTION) {
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new Register().setVisible(true);
}
});
}
}
}
}
} catch (IOException | HeadlessException ez) {
JOptionPane.showMessageDialog(null, "A null file was created in order to \n avoid File Catch errors", "Admin", JOptionPane.INFORMATION_MESSAGE);
File file = new File("data.dat");
try {
try (FileWriter writer = new FileWriter(file, true)) {
String data0 = "null";
String data1 = "null";
writer.write(data0 + " | " + data1 + "\n");
}
} catch (IOException | HeadlessException z) {
JOptionPane.showMessageDialog(null, e);
}
}
}
});
reset.setText("Reset Field");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel1)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(uname, javax.swing.GroupLayout.PREFERRED_SIZE, 300, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(login, javax.swing.GroupLayout.PREFERRED_SIZE, 137, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(reset, javax.swing.GroupLayout.PREFERRED_SIZE, 137, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(pwd))))
.addContainerGap(30, Short.MAX_VALUE)));
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(uname, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(pwd, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(login)
.addComponent(reset))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)));
pack();
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new Login().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JButton login;
private javax.swing.JPasswordField pwd;
private javax.swing.JButton reset;
private javax.swing.JTextField uname;
// End of variables declaration
}
this it the registration code it launches when I clicked yes in the confirmation box
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package login;
import java.awt.HeadlessException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JOptionPane;
/**
*
* @author Jfetizanan
*/
class Register extends javax.swing.JFrame {
/**
* Creates new form GUIREG
*/
public Register() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
unamereg = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
pwdreg = new javax.swing.JTextField();
submit = new javax.swing.JButton();
resetreg = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N
jLabel1.setText("Registration Pane");
jLabel2.setText("User Name:");
jLabel3.setText("Password:");
submit.setText("Submit");
submit.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("Runned");
File file = new File("data.dat");
try {
try (FileWriter writer = new FileWriter(file, true)) {
String data0 = unamereg.getText();
String data1 = pwdreg.getText();
writer.write(data0 + " | " + data1 + "\n");
}
JOptionPane.showMessageDialog(null, "Registered", "Registration", JOptionPane.INFORMATION_MESSAGE);
} catch (IOException | HeadlessException z) {
JOptionPane.showMessageDialog(null, e);
}
}
});
resetreg.setText("Reset Field");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel1)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(unamereg))
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(pwdreg)
.addGroup(layout.createSequentialGroup()
.addComponent(submit, javax.swing.GroupLayout.PREFERRED_SIZE, 139, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(resetreg, javax.swing.GroupLayout.PREFERRED_SIZE, 139, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 0, Short.MAX_VALUE)))))
.addContainerGap(42, Short.MAX_VALUE)));
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(unamereg, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(pwdreg, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(submit)
.addComponent(resetreg))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)));
pack();
}
/**
* @param args the command line arguments
*/
// Variables declaration - do not modify
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JTextField pwdreg;
private javax.swing.JButton resetreg;
private javax.swing.JButton submit;
private javax.swing.JTextField unamereg;
// End of variables declaration
}
Managed to find the issue through that big mess. In your if statement that pops up saying hello ‘blah’, you need to make it break out of the while loop, and move the else statement. Copy whats in the else statement just out of the while loop (just because it doesnt match the first guy, doesnt mean that it wont match a later one, so dont yell at them til the end). so have it like this:
Also, you should change Lunch registration to Launch registration 😉
In response to your comment, it’s due to this line:
You have that in both of your frames, it says to stop the JVM as soon as you close it. You want this for your login frame (if they close the login window, stop the program), but not for the registration window. For that, you just want
javax.swing.WindowConstants.DISPOSE_ON_CLOSE, which says it will dispose of the frame upon closing it (good cleanup). If all frames are disposed, the JVM will end (assuming no other threads are running that is), so as long as Login stays open, it shouldn’t exit.