package contabilidad_sgc;

import java.sql.Connection;
import com.mysql.cj.jdbc.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;

public class conectar {

     Connection conn=null;
     String bd="sistema_contabilidad";
     String login="root";
     String password="root";
     String url="jdbc:mysql://localhost/sistema_contabilidad_sgc";

     public Connection conexion(){
        try{
        Class.forName("com.mysql.cj.jdbc.Driver").newInstance();
        conn=DriverManager.getConnection(url,login,password);
        }
        catch(ClassNotFoundException e){

                JOptionPane.showMessageDialog(null, "No se pudo establecer la conexión con la base de datos "+bd);
        } catch (SQLException ex) {
            Logger.getLogger(conectar.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            Logger.getLogger(conectar.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            Logger.getLogger(conectar.class.getName()).log(Level.SEVERE, null, ex);
        }

package contabilidad_sgc;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Set;
import javax.swing.JOptionPane;
import javax.swing.JTable;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.DefaultTableModel;

/**
 *
 * @author Jeredick Escobar
 */
public class cliente extends javax.swing.JFrame {

    conectar cn = new conectar();
    Connection cc = cn.conexion();
    JTable table;
    DefaultTableModel dfm = new DefaultTableModel();
    public cliente() {
        initComponents();

        table = this.jTable1;
        table.setModel(dfm);
        dfm.setColumnIdentifiers(new Object[]{"ID","NIT","NOMBRE","DIRECCION","E-MAIL","TELEFONO","MOVIL"});
        try{
            Statement st = cc.createStatement();
            ResultSet rs= st.executeQuery("SELECT * FROM CLIENTE");

            while(rs.next()){
                dfm.addRow(new Object[]{rs.getInt("ID"),rs.getString("NIT"), rs.getString("NOMBRE"),rs.getString("DIRECCION1"),rs.getString("DIRECCION2"),rs.getInt("TELEFONO1"),rs.getInt("TELEFONO2")});
            }
            dfm.addTableModelListener(new TableModelListener() {
            @Override
            public void tableChanged(TableModelEvent e) {
                if(e.getType()==TableModelEvent.UPDATE){
                int columna = e.getColumn();
                int fila = e.getFirstRow();
                if(columna==1){
                    String sql = "UPDATE CLIENTE SET NIT = '"+jTable1.getValueAt(fila, columna)+"' WHERE ID ="+jTable1.getValueAt(fila, 0);
                    actualizar_data(sql);
                }
                }
            }
            });
        }
        catch(SQLException e){
            JOptionPane.showMessageDialog(null, "No se pudo actualizar");
        }
    }
    void actualizar_data(String act){
            try{
                PreparedStatement ps = cc.prepareStatement(act);
                ps.execute();

            }
            catch(SQLException e){
            JOptionPane.showMessageDialog(null, "No se pudo actualizar");
            }
    }

String url="jdbc:mysql://localhost/sistema_contabilidad_sgc";

Class.forName("com.mysql.cj.jdbc.Driver").newInstance();

Class.forName("com.mysql.jdbc.Driver").newInstance();