I'm doing one of the projects on youtube. Its Electricity Management System. I'm trying to run the project and send data to the database. Code below should run the project but it won't send after clicking a button.
I have an error like this:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at Electricity.New_customer.actionPerformed(New_customer.java:98) at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967) at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308) at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405) at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262) at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279) at java.desktop/java.awt.Component.processMouseEvent(Component.java:6632) at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342) at java.desktop/java.awt.Component.processEvent(Component.java:6397) at java.desktop/java.awt.Container.processEvent(Container.java:2263) at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5008) at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321) at java.desktop/java.awt.Component.dispatchEvent(Component.java:4840) at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4918) at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4547) at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4488) at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307) at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2772) at java.desktop/java.awt.Component.dispatchEvent(Component.java:4840) at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772) at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721) at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715) at java.base/java.security.AccessController.doPrivileged(Native Method) at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85) at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95) at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745) at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743) at java.base/java.security.AccessController.doPrivileged(Native Method) at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85) at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742) at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203) at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124) at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113) at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109) at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Here is my code:
package Electricity;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;
/**
*
* @author tomas
*/
public class New_customer extends JFrame implements ActionListener {
JLabel l1, l2, l3, l4, l5, l6, l7, l8;
JTextField t1, t2, t3, t4, t5, t6, t7;
JButton b1, b2;
New_customer() {
setLocation(350, 200);
setSize(650, 600);
JPanel p = new JPanel(); // declare panel as p and initialize
p.setLayout(new GridLayout(9, 2, 10, 10)); // 9 - number of rows, 2 - number of columns, 10,10 - horizontal and vertical gap between, its also adjusting size of whole window if size changed
p.setBackground(Color.WHITE);
l1 = new JLabel("Name"); // initializing new jlabel Name etc
t1 = new JTextField(); // initializing textfield etc
p.add(l1); // add label nad text field to panel p
p.add(t1);
l2 = new JLabel("Meter No");
t2 = new JTextField();
p.add(l2);
p.add(t2);
l3 = new JLabel("Address");
t3 = new JTextField();
p.add(l3);
p.add(t3);
l4 = new JLabel("State");
t4 = new JTextField();
p.add(l4);
p.add(t4);
l5 = new JLabel("City");
t5 = new JTextField();
p.add(l5);
p.add(t5);
l6 = new JLabel("Email");
t6 = new JTextField();
p.add(l6);
p.add(t6);
l7 = new JLabel("Phone Number");
t7 = new JTextField();
p.add(l7);
p.add(t7);
b1 = new JButton("Submit");
b2 = new JButton("Cancel");
b1.setBackground(Color.BLACK);
b1.setForeground(Color.WHITE);
b2.setBackground(Color.BLACK);
b2.setForeground(Color.WHITE);
p.add(b1);
p.add(b2);
setLayout(new BorderLayout());
add(p, "Center");
ImageIcon ic1 = new ImageIcon(ClassLoader.getSystemResource("icons/hicon1.jpg")); // picture
Image i3 = ic1.getImage().getScaledInstance(150, 300, Image.SCALE_DEFAULT); // rozmiar
ImageIcon ic2 = new ImageIcon(i3); // create instance of image
l8 = new JLabel(ic2);
add(l8, "West"); // add picture to West side as label 8 - l8
//for changing the color of the whole
getContentPane().setBackground(Color.WHITE); // background dookoła zdjęcia biały bez szare pola
b1.addActionListener(this);
b2.addActionListener(this);
}
public void actionPerformed(ActionEvent ae) {
String a = t1.getText();
String c = t2.getText();
String d = t3.getText();
String e = t4.getText();
String f = t5.getText();
String g = t6.getText();
String h = t7.getText();
String q1 = "insert into emp values ('" + a + "','" + c + "','" + d + "','" + e + "','" + f + "','" + g + "','" + h + "')";
try {
conn c1 = new conn();
c1.s.execute(q1);
JOptionPane.showMessageDialog(null, "Employee Created");
} catch (Exception ex) {
ex.printStackTrace();
}
}
public static void main(String[] args) {
new New_customer().setVisible(true);
}
}
