Cannot change the default background color jframe form

See more:

Java

Swing

netbeans

Hi guys,

I have a small question. I have developed a JFrame Form from scratch using Java SWING package.

The appearance is ok. I have not used a layout manager so that I have manually given the locations & the dimensions.

It also connect to a MySQL database and there aren't any issues regarding that also.

Now I want to change the default background color of the JFrame Form. I am unable to do that. Also I found that initComponents() has not declared by my self.

So that when I tried to declare getContentPane() but I couldn't do that also.

Please refer the below snippet and help me to solve the issue.

I am using NetBeans with JavaSE.

The below snippet is working fine in my development environment.

What I have tried:

/*
 * 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 javaswing;

import java.awt.Color;
import java.awt.Container;
import javax.swing.*;
import java.awt.event.*;
import java.sql.*;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Chiranthaka
 */
public class JavaSwingFirstExample {
    
    JFrame jFirstForm = new JFrame();    
      
    JLabel jLabFirstName = new JLabel("First Name");
    JLabel jLabLastName = new JLabel("Last Name");
    JLabel jLabAddress = new JLabel("Address");
    JLabel jLabAge = new JLabel("Age");
    
    JTextField jTxtFirstName = new JTextField();
    JTextField jTxtLastName = new JTextField();
    JTextField jTxtAddress = new JTextField();
    JTextField jTxtAge = new JTextField();
    
    JButton jButAdd = new JButton("Add");
    JButton jButUpdate = new JButton("Update");
    JButton jButDelete = new JButton("Delete");
    JButton jButEdit = new JButton("Edit");
    JButton jButCancel = new JButton("Cancel");
     
    JavaSwingFirstExample(){
    
    jFirstForm.setSize(400,400);
    jFirstForm.setLayout(null);
    jFirstForm.setVisible(true);
    
    //Adding controls to the form.
    jFirstForm.add(jLabFirstName);
    jFirstForm.add(jLabLastName);
    jFirstForm.add(jLabAddress);
    jFirstForm.add(jLabAge);
    
    jFirstForm.add(jTxtFirstName);
    jFirstForm.add(jTxtLastName);
    jFirstForm.add(jTxtAddress);
    jFirstForm.add(jTxtAge);
    
    jFirstForm.add(jButAdd);
    jFirstForm.add(jButUpdate);
    jFirstForm.add(jButDelete);
    jFirstForm.add(jButEdit);
    jFirstForm.add(jButCancel);
    
    //Setting the size of the controls and placing them.
    jLabFirstName.setBounds(20, 10, 150, 35);
    jLabLastName.setBounds(20, 55, 150, 35);
    jLabAddress.setBounds(20, 100, 150, 35);
    jLabAge.setBounds(20, 145, 150, 35);
    
    jTxtFirstName.setBounds(170, 10, 200, 35);
    jTxtLastName.setBounds(170, 55, 200, 35);
    jTxtAddress.setBounds(170, 100, 200, 35);
    jTxtAge.setBounds(170, 145, 200, 35);
    
    jButAdd.setBounds(30, 200, 150, 35);
    jButUpdate.setBounds(200, 200, 150, 35);
    jButDelete.setBounds(30, 255, 150, 35);
    jButEdit.setBounds(200, 255, 150, 35);
    jButCancel.setBounds(120, 310, 150, 35);
       
    //Addind an action when clicked the 'OK' button.
    jButAdd.addActionListener(new ActionListener() {
     @Override
     public void actionPerformed(ActionEvent e) {
          JOptionPane.showMessageDialog(jFirstForm, "Eggs are not supposed to be green.");
        }
    });
    
    //Addind an action when clicked the 'Cancel' button.
    jButCancel.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            clearText();
        }
    });
    
    //Setting the default close action.
    jFirstForm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   
    }
    
    public static void main(String[] args) {
        
        new JavaSwingFirstExample();   
        
        String dbURL = "jdbc:mysql://localhost:3306/basicinfo";
        String dbUser = "root";
        String dbPassword = "1234@com";
        
        try {
            Connection dbConn = DriverManager.getConnection(dbURL, dbUser, dbPassword);
            JOptionPane.showMessageDialog(null, "Sucessful. My SQL Database is now conneted!");
        } catch (SQLException ex) {
            Logger.getLogger(JavaSwingFirstExample.class.getName()).log(Level.SEVERE, null, ex);
            JOptionPane.showMessageDialog(null, "Database is not connecting!");
        }
    }
    
    private void clearText(){
        jTxtFirstName.setText("");
        jTxtLastName.setText("");
        jTxtAddress.setText("");
        jTxtAge.setText("");
    } 
        
}

Please refer the code and suggest me a solution.

Thanks,
ChiranSJ