Java con conección Mysql

MySql:

Java:

Importar  libraries click derecho

Add  JAr/Folder

mysql-connector-java-5.1.23-bin 

Crear  Formulario:

Importar:

import java.sql.*;

import javax.swing.JOptionPane;

Globales:

static Connection cn =null;

Statement st= null;

ResultSet rs=null;

En El Evento window openened:

private void formWindowOpened(java.awt.event.WindowEvent evt) {                                 

        try {

 DriverManager.registerDriver(new com.mysql.jdbc.Driver());

 cn= DriverManager.getConnection("jdbc:mysql://localhost:3306/Colegio","root","mysql");

 st= cn.createStatement();

 rs=st.executeQuery("select * from alumnos");

 if(rs.next()){

 jTextField1.setText(rs.getString(1));

 jTextField2.setText(rs.getString(2));

 jTextField3.setText(rs.getString(3));

 jTextField4.setText(rs.getString(4));

 }

        } catch (SQLException ex) {

            Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);

        }

    }   

Primer registro:

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                        

        try {

            if(rs.first()){

     jTextField1.setText(rs.getString(1));

     jTextField2.setText(rs.getString(2));

     jTextField3.setText(rs.getString(3));

     jTextField4.setText(rs.getString(4));

     }  } catch (SQLException ex) {

            Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);

        }

    }   

Anterior:      

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                        

        try {

            if(rs.previous()){

     jTextField1.setText(rs.getString(1));

     jTextField2.setText(rs.getString(2));

     jTextField3.setText(rs.getString(3));

     jTextField4.setText(rs.getString(4));

     } else{

                JOptionPane.showMessageDialog(null, "Inicio del archivo","Error",JOptionPane.INFORMATION_MESSAGE);

       

            } } catch (SQLException ex) {

            Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);

        }

    }  

Siguiente :

private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                        

        try {

            if(rs.next()){

      jTextField1.setText(rs.getString(1));

      jTextField2.setText(rs.getString(2));

      jTextField3.setText(rs.getString(3));

      jTextField4.setText(rs.getString(4));

      }else{

                JOptionPane.showMessageDialog(null, "Fin del archivo","Error",JOptionPane.INFORMATION_MESSAGE);

       

            }} catch (SQLException ex) {

       

      }

    }

Final:

private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                        

        try {

            if(rs.last()){

      jTextField1.setText(rs.getString(1));

      jTextField2.setText(rs.getString(2));

      jTextField3.setText(rs.getString(3));

      jTextField4.setText(rs.getString(4));

      } } catch (SQLException ex) {

            Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);

        }

    }