java.sql.SQLException: No value specified for parameter 2

java.sql.SQLException: No value specified for parameter 2 - java

I have here my code for login
and I am encountering this error,
"java.sql.SQLException: No value specified for parameter 2"
sometimes,
"java.sql.SQLException:Parameter index out of range (1> number of parameters, which is 0)."
I really don't have any idea.
import java.sql.*;
import javax.swing.*;
public class Login_form extends javax.swing.JFrame {
Connection conn=null;
ResultSet rs = null;
PreparedStatement pst = null;
public Login_form() {
initComponents();
conn=javaconnect.ConnecrDb();
}
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jLabel2 = new javax.swing.JLabel();
jLabel1 = new javax.swing.JLabel();
txt_password = new javax.swing.JPasswordField();
txt_user = new javax.swing.JTextField();
btn_login = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jPanel1.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "Login", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Trebuchet MS", 1, 18), new java.awt.Color(255, 153, 0))); // NOI18N
jLabel2.setText("Password:");
jLabel1.setText("Username:");
btn_login.setText("Log-In");
btn_login.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btn_loginActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addComponent(jLabel2))
.addGap(1, 1, 1)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(txt_password)
.addComponent(txt_user, javax.swing.GroupLayout.PREFERRED_SIZE, 126, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addContainerGap(100, Short.MAX_VALUE)
.addComponent(btn_login)
.addGap(36, 36, 36))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(txt_user, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel1))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(txt_password, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addComponent(btn_login)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(169, 169, 169)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGap(24, 24, 24))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(52, 52, 52)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(93, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void btn_loginActionPerformed(java.awt.event.ActionEvent evt) {
//String user=txt_user.getText();
//String pwd = txt_password.getText();
String sql = "select * from users_employee where username=? and password=?";
// JOptionPane.showMessageDialog(null, sql);
try{
pst=conn.prepareStatement(sql);
pst.setString(1,txt_user.getText());
pst.setString(1,txt_password.getText());
rs=pst.executeQuery();
if(rs.next()){
/* for(int i=1;i<4;i++)
{
}*/
JOptionPane.showMessageDialog(null, "Succesfully Login");
new home().setVisible(true);
this.hide();
}
}
catch(Exception e){
JOptionPane.showMessageDialog(null, e);
new Login_form().setVisible(true);
}
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Login_form().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton btn_login;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JPanel jPanel1;
private javax.swing.JPasswordField txt_password;
private javax.swing.JTextField txt_user;
// End of variables declaration
}

You are assigning both the user and the password to the same parameter (1).
Change this:
pst.setString(1,txt_user.getText());
pst.setString(1,txt_password.getText());
to this:
pst.setString(1,txt_user.getText());
pst.setString(2,txt_password.getText());

SQL indexes starts from zero. use the following statements,
pst.setString(0,txt_user.getText());
pst.setString(1,txt_password.getText());

Related

Why can't I return true? am I making a mistake in the database query part?

I have tried all kinds of combinations since morning but I can't return any true value. The information I entered is completely correct.
Help me pls why can't I return true? am I making a mistake in the database query part?
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.Statement;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
import java.sql.ResultSet;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* #author seyme
*/
public class para_ekle extends javax.swing.JFrame {
private boolean ahmet;
/**
* Creates new form para_ekle
*/
public para_ekle() {
initComponents();
}
static boolean ekle = false;
public void kontrol() throws SQLException{
Connection connect = null;
dbbaglanti db = new dbbaglanti();
connect = db.getConnection();
Statement oku = ( Statement) connect.createStatement();
String cekilenid = idtext4.getText();
int cevrilenid = Integer.parseInt(cekilenid);
String sifrebilgisi = sifretext4.getText();
String tutarbilgisi = idtext4.getText();
int cevrilentutar = Integer.parseInt(tutarbilgisi);
try {
}catch(Exception e){
JOptionPane.showMessageDialog(null, "Bilgilerde Bir Hata Bulunuyor!");
}
ResultSet rs;
rs = oku.executeQuery("SELECT count(id) as \"giris\" FROM dbkullanici.kullanicilar WHERE id ="+ cevrilenid +" && sifre = '"+sifrebilgisi+"'" +";");
while (rs.next()) {
int id = rs.getInt("giris");
if(id == 1){ boolean ahmet = ekle == true; } else if (id == 0 ){boolean ahmet = ekle == false;}
}
if(ahmet == true){
erortext.setText("verilerdogru");
}else if(ahmet == false){
erortext.setText("Bilgileriniz Veritabanımızda ki veriler ile eşleşmedi");
}
}
/**
* 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")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel5 = new javax.swing.JLabel();
jLabel6 = new javax.swing.JLabel();
idtext4 = new javax.swing.JTextField();
sifretext4 = new javax.swing.JTextField();
jLabel7 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
jLabel3 = new javax.swing.JLabel();
tutartext = new javax.swing.JTextField();
erortext = new javax.swing.JLabel();
jButton2 = new javax.swing.JButton();
jLabel4 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setFont(new java.awt.Font("Segoe UI Black", 1, 36)); // NOI18N
jLabel1.setText("ISSEY FİNANS SİSTEMİ");
jLabel2.setFont(new java.awt.Font("Ink Free", 1, 14)); // NOI18N
jLabel2.setText("ISSEY ile paralarınız daha değerli");
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap(37, Short.MAX_VALUE)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 428, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(32, 32, 32))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 214, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(128, 128, 128))))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(22, 22, 22)
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 18, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
jLabel5.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jLabel5.setText("Hesap Şifreniz: ");
jLabel6.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jLabel6.setText("Hesap İd Numaranızı Yazınız: ");
idtext4.setText("jTextField1");
sifretext4.setText("jTextField2");
jLabel7.setText("İd Numaranızı Bilmiyorsanız Kullanıcı listeleme panelinden görüntüleyebilirsiniz.");
jButton1.setText("Ana Menü'ye Dön");
jLabel3.setFont(new java.awt.Font("Tahoma", 0, 12)); // NOI18N
jLabel3.setText("Eklemek İstediğiniz Tutar");
tutartext.setText("jTextField1");
erortext.setForeground(new java.awt.Color(255, 0, 0));
jButton2.setText("Para Ekle");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jLabel4.setForeground(new java.awt.Color(102, 102, 102));
jLabel4.setText(" Para Eklemi işlemi için tüm bilgileri büyük küçük harf ve boşluk dahil doğru girmelisiniz.");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(erortext, javax.swing.GroupLayout.PREFERRED_SIZE, 390, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(55, 55, 55))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 0, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jLabel7)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel6, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 188, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(jLabel3, javax.swing.GroupLayout.PREFERRED_SIZE, 142, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(26, 26, 26)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(idtext4)
.addComponent(sifretext4)
.addComponent(tutartext, javax.swing.GroupLayout.PREFERRED_SIZE, 124, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(layout.createSequentialGroup()
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 119, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 118, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(8, 8, 8)))
.addGap(61, 61, 61))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jLabel4, javax.swing.GroupLayout.PREFERRED_SIZE, 408, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(23, 23, 23))))))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jLabel7)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel6, javax.swing.GroupLayout.PREFERRED_SIZE, 34, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(idtext4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 27, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(sifretext4, 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(tutartext, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel4)
.addGap(16, 16, 16)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 35, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 35, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(erortext, javax.swing.GroupLayout.DEFAULT_SIZE, 50, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
try {
kontrol();
} catch (SQLException ex) {
Logger.getLogger(para_ekle.class.getName()).log(Level.SEVERE, null, ex);
}
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(para_ekle.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(para_ekle.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(para_ekle.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(para_ekle.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new para_ekle().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JLabel erortext;
private javax.swing.JTextField idtext4;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JLabel jLabel7;
private javax.swing.JPanel jPanel1;
private javax.swing.JTextField sifretext4;
private javax.swing.JTextField tutartext;
// End of variables declaration
}

Java GUI freeze when clicking jButton

this is my Java GUI first try i don't know which one is error. When i press jbutton my GUI stuck.
Please assist
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package latihancrud;
import java.sql.Connection;
import javax.swing.JOptionPane;
/**
*
* #author agungmahaputra
*/
public class menu extends javax.swing.JFrame {
/**
* Creates new form menu
*/
public menu() {
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")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
jLabel5 = new javax.swing.JLabel();
jLabel6 = new javax.swing.JLabel();
txtName = new javax.swing.JTextField();
txtNIS = new javax.swing.JTextField();
txtAddress = new javax.swing.JTextField();
txtEmail = new javax.swing.JTextField();
txtJurusan = new javax.swing.JTextField();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jButton4 = new javax.swing.JButton();
jButton6 = new javax.swing.JButton();
jScrollPane1 = new javax.swing.JScrollPane();
jTable1 = new javax.swing.JTable();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setText("NIS");
jLabel2.setText("Data Siswa");
jLabel3.setText("Nama");
jLabel4.setText("Jurusan");
jLabel5.setText("Alamat");
jLabel6.setText("Email");
jButton2.setText("Edit");
jButton3.setText("Add");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
jButton4.setText("Delete");
jButton6.setText("Clear");
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(187, 187, 187)
.addComponent(jLabel2))
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(21, 21, 21)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel6)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtEmail, javax.swing.GroupLayout.PREFERRED_SIZE, 178, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel5)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtAddress, javax.swing.GroupLayout.PREFERRED_SIZE, 178, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtName, javax.swing.GroupLayout.PREFERRED_SIZE, 178, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtNIS, javax.swing.GroupLayout.PREFERRED_SIZE, 178, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel4)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 29, Short.MAX_VALUE)
.addComponent(txtJurusan, javax.swing.GroupLayout.PREFERRED_SIZE, 178, javax.swing.GroupLayout.PREFERRED_SIZE)))))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 38, Short.MAX_VALUE)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton6, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(28, 28, 28))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(15, 15, 15)
.addComponent(jLabel2)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(25, 25, 25)
.addComponent(jButton3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton2)
.addGap(69, 69, 69)
.addComponent(jButton4)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton6))
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(txtNIS, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel1))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(txtName, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel5)
.addComponent(txtAddress, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel6)
.addComponent(txtEmail, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel4)
.addComponent(txtJurusan, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
jTable1.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
{null, null, null, null},
{null, null, null, null},
{null, null, null, null},
{null, null, null, null}
},
new String [] {
"Title 1", "Title 2", "Title 3", "Title 4"
}
));
jScrollPane1.setViewportView(jTable1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(262, 262, 262)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(298, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane1)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(16, 16, 16)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
try{
String sql = "INSERT INTO tbStudent VALUES ('"+txtNIS.getText()+"','"+txtName.getText()+"','"+txtAddress.getText()+"','"+txtEmail.getText()+"','"+txtJurusan.getText()+"')";
java.sql.Connection conn=(Connection)connection.configDB();
java.sql.PreparedStatement pst = conn.prepareStatement(sql);
pst.execute();
JOptionPane.showMessageDialog(null, "Sukses menambahkan data");
}catch(Exception e){
JOptionPane.showMessageDialog(this, e.getMessage());
}
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(menu.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(menu.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(menu.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(menu.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new menu().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JButton jButton4;
private javax.swing.JButton jButton6;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTable jTable1;
private javax.swing.JTextField txtAddress;
private javax.swing.JTextField txtEmail;
private javax.swing.JTextField txtJurusan;
private javax.swing.JTextField txtNIS;
private javax.swing.JTextField txtName;
// End of variables declaration
}

As I already stated in my comment, you need to read the article about concurrency in Swing. To solve your freezing problem you need to move your code that calls database operations in another thread. The best way to do it is to use SwingWorker. Here is how it will look in your code
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String sql = "INSERT INTO tbStudent VALUES ('"+txtNIS.getText()+"','"+txtName.getText()+"','"+txtAddress.getText()+"','"+txtEmail.getText()+"','"+txtJurusan.getText()+"')";
java.sql.Connection conn=(Connection)connection.configDB();
java.sql.PreparedStatement pst = conn.prepareStatement(sql);
SwingWorker<Boolean, Void> worker = new SwingWorker<Boolean, Void>() {
private String message;
#Override
protected Boolean doInBackground() throws Exception {
try {
return pst.execute();
} catch (Exception e) {
message = e.getMessage();
return false;
}
}
#Override
protected void done() {
if (get()) {
JOptionPane.showMessageDialog(null, "Sukses menambahkan data");
} else {
JOptionPane.showMessageDialog(menu.this, message);
}
}
};
worker.execute();
}
I've not tested this solution. If it doesn't work, please let me know.

Java: NullPointerException in Jframe when hiding buttons

I am working on a quiz for a school assignment and i am attempting to create a GUI using JFrame. I had an idea to make all the buttons invisible and only appear after clicking the start button. However when I attempted to do so by using the .setVisible(false) command in the main method, it gives me a nullpointerexception. I am unsure about whats wrong and I am hoping someone could give me some pointers. Here's my code:
import javax.swing.JOptionPane;
public class QuizGUI extends javax.swing.JFrame {
/**
* Creates new form QuizGUI
*/
public QuizGUI() {
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")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jButton4 = new javax.swing.JButton();
jPanel1 = new javax.swing.JPanel();
Q1 = new javax.swing.JButton();
jPanel2 = new javax.swing.JPanel();
Q2 = new javax.swing.JButton();
jPanel3 = new javax.swing.JPanel();
Q3 = new javax.swing.JButton();
jPanel4 = new javax.swing.JPanel();
Q4 = new javax.swing.JButton();
jPanel5 = new javax.swing.JPanel();
Q5 = new javax.swing.JButton();
jPanel7 = new javax.swing.JPanel();
Bonus = new javax.swing.JButton();
Exit = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jPanel6 = new javax.swing.JPanel();
Start = new javax.swing.JButton();
EndQuiz = new javax.swing.JButton();
Timer = new javax.swing.JLabel();
jButton4.setText("jButton4");
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
Q1.setText("Question 1");
Q1.addChangeListener(new javax.swing.event.ChangeListener() {
public void stateChanged(javax.swing.event.ChangeEvent evt) {
Q1StateChanged(evt);
}
});
Q1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
Q1ActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addGap(33, 33, 33)
.addComponent(Q1, javax.swing.GroupLayout.DEFAULT_SIZE, 145, Short.MAX_VALUE)
.addContainerGap())
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(Q1, javax.swing.GroupLayout.PREFERRED_SIZE, 47, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(11, 11, 11))
);
Q1.getAccessibleContext().setAccessibleName("Question1");
Q2.setText("Question 2");
Q2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
Q2ActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
.addContainerGap(35, Short.MAX_VALUE)
.addComponent(Q2, javax.swing.GroupLayout.PREFERRED_SIZE, 146, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(13, 13, 13)
.addComponent(Q2, javax.swing.GroupLayout.PREFERRED_SIZE, 47, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
Q2.getAccessibleContext().setAccessibleName("Question2");
Q3.setText("Question 3");
Q3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
Q3ActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
jPanel3.setLayout(jPanel3Layout);
jPanel3Layout.setHorizontalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel3Layout.createSequentialGroup()
.addContainerGap(32, Short.MAX_VALUE)
.addComponent(Q3, javax.swing.GroupLayout.PREFERRED_SIZE, 149, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(9, 9, 9))
);
jPanel3Layout.setVerticalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addContainerGap()
.addComponent(Q3, javax.swing.GroupLayout.DEFAULT_SIZE, 46, Short.MAX_VALUE)
.addContainerGap())
);
Q3.getAccessibleContext().setAccessibleName("Question3");
Q4.setText("Question 4");
Q4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
Q4ActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4);
jPanel4.setLayout(jPanel4Layout);
jPanel4Layout.setHorizontalGroup(
jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel4Layout.createSequentialGroup()
.addContainerGap(38, Short.MAX_VALUE)
.addComponent(Q4, javax.swing.GroupLayout.PREFERRED_SIZE, 147, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
jPanel4Layout.setVerticalGroup(
jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel4Layout.createSequentialGroup()
.addGap(13, 13, 13)
.addComponent(Q4, javax.swing.GroupLayout.PREFERRED_SIZE, 46, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
Q4.getAccessibleContext().setAccessibleName("Question4\n");
Q5.setText("Question 5");
Q5.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
Q5ActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel5Layout = new javax.swing.GroupLayout(jPanel5);
jPanel5.setLayout(jPanel5Layout);
jPanel5Layout.setHorizontalGroup(
jPanel5Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel5Layout.createSequentialGroup()
.addGap(37, 37, 37)
.addComponent(Q5, javax.swing.GroupLayout.PREFERRED_SIZE, 147, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(34, Short.MAX_VALUE))
);
jPanel5Layout.setVerticalGroup(
jPanel5Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel5Layout.createSequentialGroup()
.addGap(13, 13, 13)
.addComponent(Q5, javax.swing.GroupLayout.PREFERRED_SIZE, 50, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
Q5.getAccessibleContext().setAccessibleName("Question5");
Bonus.setText("Bonus");
Bonus.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
BonusActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel7Layout = new javax.swing.GroupLayout(jPanel7);
jPanel7.setLayout(jPanel7Layout);
jPanel7Layout.setHorizontalGroup(
jPanel7Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel7Layout.createSequentialGroup()
.addGap(9, 9, 9)
.addComponent(Bonus)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
jPanel7Layout.setVerticalGroup(
jPanel7Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel7Layout.createSequentialGroup()
.addGap(31, 31, 31)
.addComponent(Bonus)
.addContainerGap(34, Short.MAX_VALUE))
);
Exit.setText("Exit");
Exit.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
ExitActionPerformed(evt);
}
});
jLabel1.setFont(new java.awt.Font("Vivaldi", 1, 48)); // NOI18N
jLabel1.setText("Quiz");
jLabel2.setFont(new java.awt.Font("Tahoma", 0, 35)); // NOI18N
Start.setText("Start");
Start.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
StartActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel6Layout = new javax.swing.GroupLayout(jPanel6);
jPanel6.setLayout(jPanel6Layout);
jPanel6Layout.setHorizontalGroup(
jPanel6Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel6Layout.createSequentialGroup()
.addComponent(Start)
.addGap(0, 32, Short.MAX_VALUE))
);
jPanel6Layout.setVerticalGroup(
jPanel6Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel6Layout.createSequentialGroup()
.addContainerGap()
.addComponent(Start)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
EndQuiz.setText("End Quiz");
EndQuiz.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
EndQuizActionPerformed(evt);
}
});
Timer.setText("jLabel3");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel7, javax.swing.GroupLayout.PREFERRED_SIZE, 110, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(73, 73, 73)
.addComponent(EndQuiz)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 92, Short.MAX_VALUE)
.addComponent(Exit, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel2)
.addGap(116, 116, 116))
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jPanel6, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(0, 0, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel5, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(Timer)
.addGap(71, 71, 71))))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1)
.addComponent(jLabel2))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(EndQuiz)
.addGap(56, 56, 56))
.addGroup(layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, 76, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(26, 26, 26)
.addComponent(jPanel6, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(22, 22, 22)
.addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, 77, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jPanel5, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(70, 70, 70)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jPanel7, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(Exit, javax.swing.GroupLayout.PREFERRED_SIZE, 44, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(Timer)
.addGap(168, 168, 168))))))
);
pack();
}// </editor-fold>
private void Q1StateChanged(javax.swing.event.ChangeEvent evt) {
// TODO add your handling code here:
}
private void Q1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String Q1 = (String) JOptionPane.showInputDialog( //Question 1
null,
Question.getQuestionMCQ(1),
"Q1",
JOptionPane.QUESTION_MESSAGE,
null,
Question.Options(0),
Question.Options(0)[1]
);
JOptionPane.showMessageDialog(
null,
Question.checkAnswerMCQ (Q1,1));
if (Question.getScore()<1) {
jLabel2.setText(Integer.toString(Question.getScore()));
Q2.setVisible(true); //Q1
}
else {}
}
private void Q2ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String Q2 = (String) JOptionPane.showInputDialog( //Question 2
null,
Question.getQuestionMCQ(2),
"Q2",
JOptionPane.QUESTION_MESSAGE,
null,
Question.Options(1),
Question.Options(1)[1]
);
JOptionPane.showMessageDialog(
null,
Question.checkAnswerMCQ (Q2,2));
if (Question.getScore()<2) {
jLabel2.setText(Integer.toString(Question.getScore()));
Q3.setVisible(true); //Q2
}
else {}
}
private void Q3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String Q3 = JOptionPane.showInputDialog(
null,
Question.getQuestionOE(1),
"Q3",
JOptionPane.QUESTION_MESSAGE);
JOptionPane.showMessageDialog(
null,
Question.checkAnswerOE(Q3, 1));
if (Question.getScore() <3) {
jLabel2.setText(Integer.toString(Question.getScore()));
Q4.setVisible(true); //Q3
}
else {}
}
private void Q4ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String Q4 = JOptionPane.showInputDialog(
null,
Question.getQuestionOE(2),
"Q4",
JOptionPane.QUESTION_MESSAGE);
JOptionPane.showMessageDialog(
null,
Question.checkAnswerOE(Q4, 2));
if (Question.getScore() < 4) {
jLabel2.setText(Integer.toString(Question.getScore()));
Q5.setVisible(true); //Q4
}
else {}
}
private void Q5ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String Q5 = JOptionPane.showInputDialog(
null,
Question.getQuestionOE(3),
"Q5",
JOptionPane.QUESTION_MESSAGE);
JOptionPane.showMessageDialog(
null,
Question.checkAnswerOE(Q5, 3));
if (Question.getScore() < 5) {
jLabel2.setText(Integer.toString(Question.getScore()));
EndQuiz.setVisible(true);
}
else if (Question.getScore()==5) {
Bonus.setVisible(true);
}
else {}
}
private void BonusActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
BonusButtonPicture s =new BonusButtonPicture();
s.setVisible(true);
}
private void ExitActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
System.exit(0);
}
private void StartActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
jLabel2.setText(Integer.toString(Question.restartScore()));
Q1.setVisible(true);
Start.setVisible(false);
}
private void EndQuizActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
JOptionPane.showMessageDialog(null, "Thanks for taking the quiz! You have acheived a score of " +Question.getScore());
int retry = JOptionPane.showConfirmDialog(null, "Do you want to take the quiz again?");
switch (retry) {
case JOptionPane.NO_OPTION: //ends the program
JOptionPane.showMessageDialog(null,"End of quiz");
System.exit(0);
break;
case JOptionPane.YES_OPTION: jLabel2.setText(Integer.toString(Question.restartScore())); //restarts
Question.randomizeQuestionsMCQ();
Question.randomizeQuestionsOpenEnded();
Start.setVisible(true);
break;
case JOptionPane.CLOSED_OPTION: System.exit(0); //closes the program
}
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
Question.randomizeQuestionsMCQ();
Question.randomizeQuestionsOpenEnded();
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(QuizGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(QuizGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(QuizGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(QuizGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(() -> {
new QuizGUI().setVisible(true);
});
Q1.setVisible(false);
Q2.setVisible(false);
Q3.setVisible(false);
Q4.setVisible(false);
Q5.setVisible(false);
Bonus.setVisible(false);
EndQuiz.setVisible(false);
}
// Variables declaration - do not modify
private static javax.swing.JButton Bonus;
private static javax.swing.JButton EndQuiz;
private javax.swing.JButton Exit;
private static javax.swing.JButton Q1;
private static javax.swing.JButton Q2;
private static javax.swing.JButton Q3;
private static javax.swing.JButton Q4;
private static javax.swing.JButton Q5;
private static javax.swing.JButton Start;
private static javax.swing.JLabel Timer;
private javax.swing.JButton jButton4;
private javax.swing.JLabel jLabel1;
private static javax.swing.JLabel jLabel2;
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
private javax.swing.JPanel jPanel3;
private javax.swing.JPanel jPanel4;
private javax.swing.JPanel jPanel5;
private javax.swing.JPanel jPanel6;
private javax.swing.JPanel jPanel7;
// End of variables declaration
}
The error appears in the main method
public static void main(String args[]) {
//code
Q1.setVisible(false); //Error here
Q2.setVisible(false);
Q3.setVisible(false);
Q4.setVisible(false);
Q5.setVisible(false);
Bonus.setVisible(false);
EndQuiz.setVisible(false);
}
Thanks in advance!

You are initializing the buttons inside the constructor of your class which is called after the
Q1.setVisible(false);
Q2.setVisible(false);
Q3.setVisible(false);
Q4.setVisible(false);
Q5.setVisible(false);
Bonus.setVisible(false);
EndQuiz.setVisible(false);
part of code which causes the exception. What you need to do is include this snippet inside
/* Create and display the form */
java.awt.EventQueue.invokeLater(() -> {
new QuizGUI().setVisible(true);
});
and it should be OK.

java.sql.sqlexception: no suitable driver for (database link)

When I run my application I got this message (java.sql.sqlexception: no suitable driver for (database link))
I searched for more the 13 hours and tried more than 10 solutions so..
this my connection code
package khaledbayzav0.pkg1;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import javax.swing.*;
public class MySQLconn {
public static Connection mkmbhs(){
try{
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/fuchs","root","mkmbhs");
Statement stmt = (Statement) con.createStatement();
}
catch(SQLException e){
JOptionPane.showMessageDialog(null, e);
}
return null;
}
}
and this the actions of Db (My Buttons and fields (jFrame)
package khaledbayzav0.pkg1;
import java.awt.event.* ;
import java.awt.* ;
import java.sql.*;
import javax.swing.JOptionPane;
import javax.swing.*;
public class NewCustomers extends javax.swing.JFrame {
Connection con = null;
ResultSet rs = null;
PreparedStatement pst = null;
public NewCustomers() {
initComponents();
con = MySQLconn.mkmbhs();
}
#SuppressWarnings("unchecked")
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jPanel2 = new javax.swing.JPanel();
jLabel5 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
name = new javax.swing.JTextField();
tele = new javax.swing.JTextField();
adrs = new javax.swing.JTextField();
sv = new javax.swing.JTextField();
add = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jLabel6 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
jPanel1.setBackground(new java.awt.Color(255, 255, 255));
jPanel1.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "New Customer Form", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Times New Roman", 1, 11))); // NOI18N
jLabel5.setText("Supervisor:");
jLabel4.setText("Address:");
jLabel3.setText("Telphone:");
jLabel2.setText("Customer Name:");
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addComponent(jLabel3)
.addComponent(jLabel4)
.addComponent(jLabel5))
.addGap(79, 79, 79)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(sv, javax.swing.GroupLayout.DEFAULT_SIZE, 301, Short.MAX_VALUE)
.addComponent(adrs)
.addComponent(tele)
.addComponent(name))
.addContainerGap(55, Short.MAX_VALUE))
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addComponent(name, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(tele, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(adrs, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(sv, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel2Layout.createSequentialGroup()
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel4)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel5)))
.addContainerGap(23, Short.MAX_VALUE))
);
add.setText("ADD");
add.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
addActionPerformed(evt);
}
});
jButton2.setText("BACK");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jLabel6.setFont(new java.awt.Font("Blackadder ITC", 0, 12)); // NOI18N
jLabel6.setForeground(new java.awt.Color(204, 0, 0));
jLabel6.setText("Designed By Mkmbhs");
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addGap(58, 58, 58)
.addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 174, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 99, Short.MAX_VALUE)
.addComponent(add, javax.swing.GroupLayout.PREFERRED_SIZE, 174, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(40, 40, 40))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addContainerGap(230, Short.MAX_VALUE)
.addComponent(jLabel6)
.addGap(219, 219, 219))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(32, 32, 32)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(add)
.addComponent(jButton2))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 28, Short.MAX_VALUE)
.addComponent(jLabel6)
.addContainerGap())
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
pack();
}// </editor-fold>
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
close();
CustomersSelection CS = new CustomersSelection();
CS.setVisible(true);
}
private void addActionPerformed(java.awt.event.ActionEvent evt) {
try {
String sql = "INSERT INTO customerinof(CustomerName, CustomerAddress, CustomerTelephone, CustomerSupervisor) values (?,?,?,?)";
pst = con.prepareStatement(sql);
pst.setString(1, name.getText());
pst.setString(2, adrs.getText());
pst.setString(3, tele.getText());
pst.setString(4, sv.getText());
pst.execute();
JOptionPane.showMessageDialog(null, "New Customer added to your table ");
}
catch (Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewCustomers().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton add;
private javax.swing.JTextField adrs;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
private javax.swing.JTextField name;
private javax.swing.JTextField sv;
private javax.swing.JTextField tele;
// End of variables declaration
private void close() {
WindowEvent closeW = new WindowEvent(this,WindowEvent.WINDOW_CLOSING);
Toolkit.getDefaultToolkit().getSystemEventQueue().postEvent(closeW);
}
}

Put your mysql driver jar (mysql-connector.jar) in your server lib folder. This need to be present in the classpath for interacting with the database.

You are not loading driver class
Class.forName("com.mysql.jdbc.Driver");
Have a look at the MySQL docs
You need mysql-connector jar in class path to load above Driver class.
You can download it from MySQL site
Related Links
Connecting to MySQL Using the JDBC DriverManager Interface
Add-JARs-to-Project-Build-Paths-in-Eclipse-(Java)

database reading issue with Java and php

Below is the Java code, trying to connect to a mysql database using php script, the connection is established but there is a problem in reading and inserting tables.
Any recommendation is greatly appreciate it, Both Java and php codes are given :
package tc21reserve;
import java.net.*;
import java.io.*;
public class TC21Create extends javax.swing.JApplet {
#Override
public void init() {
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(TC21Create.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(TC21Create.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(TC21Create.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(TC21Create.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the applet */
try {
java.awt.EventQueue.invokeAndWait(new Runnable() {
public void run() {
initComponents();
}
});
} catch (Exception ex) {
ex.printStackTrace();
}
}
/**
* This method is called from within the init() method to initialize the
* form. WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jSeparator1 = new javax.swing.JSeparator();
jLabel2 = new javax.swing.JLabel();
jTextField1 = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
jComboBox1 = new javax.swing.JComboBox();
jLabel4 = new javax.swing.JLabel();
jComboBox2 = new javax.swing.JComboBox();
jLabel5 = new javax.swing.JLabel();
jComboBox3 = new javax.swing.JComboBox();
jLabel6 = new javax.swing.JLabel();
jTextField2 = new javax.swing.JTextField();
jLabel7 = new javax.swing.JLabel();
jComboBox4 = new javax.swing.JComboBox();
jLabel8 = new javax.swing.JLabel();
jTextField3 = new javax.swing.JTextField();
jLabel9 = new javax.swing.JLabel();
jTextField4 = new javax.swing.JTextField();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jLabel1.setText("New Reservation");
jLabel2.setText("License #: ");
jLabel3.setText("Site: ");
jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Garage A", "Garage B" }));
jLabel4.setText("Floor:");
jComboBox2.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "1", "2" }));
jLabel5.setText("Spot:");
jComboBox3.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "101", "102", "103", "104", "105", "106", "107", "108", "109", "110", "201", "202", "203", "204", "205", "206", "207", "208", "209", "210" }));
jLabel6.setText("Reservation Date(MM/DD/YYYY):");
jLabel7.setText("Duration:");
jComboBox4.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Hourly", "Daily", "Weekly", "Monthly", " " }));
jLabel8.setText("Credit Card:");
jLabel9.setText("Expiration Date(MM/YYYY):");
jButton1.setText("Submit");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton2.setText("Clear");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jSeparator1))
.addGroup(layout.createSequentialGroup()
.addGap(159, 159, 159)
.addComponent(jLabel1))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addComponent(jLabel6)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField2))
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jLabel4)
.addComponent(jLabel7))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jComboBox2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel5)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jComboBox3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(jComboBox4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))))
.addContainerGap())
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel8)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, 84, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jLabel9)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField4, javax.swing.GroupLayout.PREFERRED_SIZE, 64, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton2)
.addGap(14, 14, 14))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addGap(18, 18, 18)
.addComponent(jSeparator1, javax.swing.GroupLayout.PREFERRED_SIZE, 10, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel3)
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel4)
.addComponent(jComboBox2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel5)
.addComponent(jComboBox3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(24, 24, 24)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel6)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel7)
.addComponent(jComboBox4, 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(jLabel8)
.addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel9)
.addComponent(jTextField4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 92, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1)
.addComponent(jButton2))
.addGap(19, 19, 19))
);
}// </editor-fold>//GEN-END:initComponents
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
try {
// open a connection to the site
Dsend();
} catch (Exception ex) {
}
}//GEN-LAST:event_jButton1ActionPerformed
// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JComboBox jComboBox1;
private javax.swing.JComboBox jComboBox2;
private javax.swing.JComboBox jComboBox3;
private javax.swing.JComboBox jComboBox4;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JLabel jLabel7;
private javax.swing.JLabel jLabel8;
private javax.swing.JLabel jLabel9;
private javax.swing.JSeparator jSeparator1;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextField jTextField2;
private javax.swing.JTextField jTextField3;
private javax.swing.JTextField jTextField4;
// End of variables declaration//GEN-END:variables
public void Dsend() throws Exception {
URL hp = new URL("http://www.luxuryparking.comeze.com/DBinput.php");
HttpURLConnection hpCon = (HttpURLConnection) hp.openConnection();
hpCon.setRequestMethod("POST");
hpCon.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
hpCon.setRequestProperty("Content-Language", "en-US");
hpCon.setUseCaches (false);
hpCon.setDoOutput(true);
// important: get output stream before input stream
DataOutputStream ps = new DataOutputStream (hpCon.getOutputStream());
ps.writeBytes("license=" + URLEncoder.encode(jTextField1.getText(), "UTF-8"));
hpCon.getInputStream();`enter code here`
// close the print stream
ps.flush ();
ps.close ();
} }
// Java code Done
// And below is the php script :
<?php
// Connects to your Database
$host="mysql17.000webhost.com"; // Host name
$username="username"; // Mysql username
$password="password"; // Mysql password
$db_name="a4335408_data1"; // Database name
$tbl_name="Reservation"; // Table name
$conn = new PDO("mysql:host=$host;dbname=a4335408_data1", $username, $password);
for each ($_POST as $key => $value) {
switch ($key) {
case 'license':
$license = $value;
break;
default:
break;
}
}
$license=$_POST['license'];
$sql = "INSERT INTO Reservation (LicensePlate) VALUES (:license)";
$q = $conn->prepare($sql);
$q->execute(array(':license'=>$license));
?>

Develop Reference

Java is a programming language and computing platform first released by Sun Microsystems in 1995.

java.sql.SQLException: No value specified for parameter 2 - java

You are assigning both the user and the password to the same parameter (1). Change this: pst.setString(1,txt_user.getText()); pst.setString(1,txt_password.getText()); to this: pst.setString(1,txt_user.getText()); pst.setString(2,txt_password.getText());

SQL indexes starts from zero. use the following statements, pst.setString(0,txt_user.getText()); pst.setString(1,txt_password.getText());

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