java data base with jform connection

java data base with jform connection :

links : http://www.homeandlearn.co.uk/java/databases_and_java_forms.html

http://www.homeandlearn.co.uk/java/databases_and_java_forms.html

http://www.java-forums.org/new-java/63794-gui-nullpointerexception.html

http://ideone.com/RzLiJT

http://henry416.wordpress.com/2012/01/10/how-to-bind-data-from-database-with-java-swing-ui/

http://henry416.wordpress.com/2012/01/12/query-database-using-swing-ui/

http://stackoverflow.com/questions/13766262/database-scrolling-buttons-using-java-forms-error-when-calling-next-method-to


code :
---------


/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package Employees;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
import javax.swing.JOptionPane;


/**
 *
 * @author backup
 */
public class Workers extends javax.swing.JFrame {

    /**
     * Creates new form Workers
     */
    //VARIBALE DECLARATION
    Connection con;
    Statement stmt;
    ResultSet rs;
    //WORKERS CONSTRUCTOR 
    
    public Workers() {
        initComponents();
      DoConnect();
        }
    public void DoConnect(){
        try{
            //CONNECT TO THE DATABASE
            String host = "jdbc:derby://localhost:1527/Employees ";
            String uName = "riyo";
            String uPassword = "iw123456";
            con = DriverManager.getConnection(host,uName,uPassword);
            //EXECUTE SOME SQL AND LOAD THE RECORDS 
            
           stmt = con.createStatement();
           String sql = "SELECT*FROM WORKERS";
           rs = stmt.executeQuery(sql);
           
           
           //CALL FIRST RECORD DATA AND GET DATA
           rs.next() ;
           int id_col = rs.getInt("ID");
           String id = Integer.toString(id_col);
           String First = rs.getString("First_Name");
           String Last = rs.getString("Last_Name");
           String Job = rs.getString("Job_Title");
           
           
           //DISPLAY THE FIRST RECORD IN TEH TEXT FIELDS 
           textID.setText(id);
           textFirstName.setText(First);
           textLastName.setText(Last);
           textJobTitle.setText(Job);
        }
        catch( SQLException err ){
            JOptionPane.showMessageDialog(Workers.this, err.getMessage());
           
    }
    }

    /**
     * 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() {

        textID = new javax.swing.JTextField();
        textFirstName = new javax.swing.JTextField();
        textLastName = new javax.swing.JTextField();
        jLabel1 = new javax.swing.JLabel();
        textJobTitle = new javax.swing.JTextField();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        textID.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                textIDActionPerformed(evt);
            }
        });

        textFirstName.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                textFirstNameActionPerformed(evt);
            }
        });

        jLabel1.setFont(new java.awt.Font("Tahoma", 1, 12)); // NOI18N
        jLabel1.setText("JobTitle:");

        textJobTitle.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                textJobTitleActionPerformed(evt);
            }
        });

        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(30, 30, 30)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(textID, javax.swing.GroupLayout.PREFERRED_SIZE, 50, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 64, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(47, 47, 47)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(textFirstName, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(80, 80, 80)
                        .addComponent(textLastName, javax.swing.GroupLayout.PREFERRED_SIZE, 120, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addComponent(textJobTitle, javax.swing.GroupLayout.PREFERRED_SIZE, 275, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(234, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(29, 29, 29)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(textID, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(textFirstName, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(textLastName, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(58, 58, 58)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(textJobTitle, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(204, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void textIDActionPerformed(java.awt.event.ActionEvent evt) {                                       
        // TODO add your handling code here:
    }                                      

    private void textFirstNameActionPerformed(java.awt.event.ActionEvent evt) {                                              
        // TODO add your handling code here:
    }                                             

    private void textJobTitleActionPerformed(java.awt.event.ActionEvent evt) {                                             
        // TODO add your handling code here:
    }                                            

    /**
     * @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(Workers.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Workers.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Workers.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Workers.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 Workers().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JLabel jLabel1;
    private javax.swing.JTextField textFirstName;
    private javax.swing.JTextField textID;
    private javax.swing.JTextField textJobTitle;
    private javax.swing.JTextField textLastName;
    // End of variables declaration                   
}