Primeiramente fazemos a classe de conexão.
[code]/*
- To change this template, choose Tools | Templates
- and open the template in the editor.
*/
package Conexao.bd;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
*
-
@Thiago Gonçalves Fonseca
*/
public class Conexao {
final private String driver = “com.mysql.jdbc.Driver”;
final private String url = “jdbc:mysql://localhost:3306/supercredjava”;
final private String usuario = “root”;
final private String senha = “root”;
private Connection conexao;
public Statement statement;
public ResultSet resultset;
public boolean conecta() {
boolean result = true;
try {
Class.forName(driver);
conexao = DriverManager.getConnection(url, usuario, senha);
System.out.println(“CONECTOU”);
} catch (ClassNotFoundException Driver) {
System.out.println("DRIVER NÃ?O LOCALIZADO " + Driver);
result = false;
} catch (SQLException Fonte) {
System.out.println("DEU ERRO NA CONEXÃ?O " + “COM A FONTE DE DADOS” + Fonte);
result = false;
}
return result;
}
public void desconecta() {
boolean result = true;
try {
conexao.close();
System.out.println(“Conexão com banco FECHADA”);
} catch (SQLException fecha) {
System.out.println("NÃ?O FOI POSSIVEL " + "FECHAR O BANCO DE DADOS " + fecha);
result = false;
}
}
public void executeSQL(String sql) {
try {
statement = conexao.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
resultset = statement.executeQuery(sql);
} catch (SQLException sqlex) {
System.out.println("executeSQL: NÃ?O FOI POSSIVEL " + “EXECUTAR O COMANDO sql " + sqlex + " , o sql passado foi: \n” + sql);
}
}
public void executeUpdate(String sqlupdate) {
try {
statement = conexao.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
statement.executeUpdate(sqlupdate);
} catch (SQLException ex) {
ex.printStackTrace();
}
}
}
[/code]
Vamos a consulta.
/*
* Principal.java
*
* Created on 23/06/2010, 23:43:21
* Projeto criado originalmente no Netbeans 6.8
*/
package ConsultaClientecombo.view;
import Conexao.bd.Conexao;
import java.awt.event.ItemEvent;
import java.sql.SQLException;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
/**
*
* @Thiago Gonçalves Fonseca
* Consulta Clientes
*
*/
public class Principal extends javax.swing.JFrame {
private Conexao con_cli = new Conexao();
private String codcli = null;
/** Construtor desta classe */
public Principal() {
initComponents();
//método responsável por inserir os clientes do BD no JComboBox
setComboClientes();
//Metodo para mudar a aparencia de alguns itens
setAparencia();
}
/** 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">//GEN-BEGIN:initComponents
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jComboBox1 = new javax.swing.JComboBox();
jLabel2 = new javax.swing.JLabel();
jTextField1 = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
jTextField2 = new javax.swing.JTextField();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jLabel4 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setText("Clientes: ");
jComboBox1.addItemListener(new java.awt.event.ItemListener() {
public void itemStateChanged(java.awt.event.ItemEvent evt) {
jComboBox1ItemStateChanged(evt);
}
});
jLabel2.setText("Codigo cliente: ");
jTextField1.setEnabled(false);
jLabel3.setText("Nome Cliente:");
jButton1.setText("Gravar");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton2.setText("Sair");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jLabel4.setFont(new java.awt.Font("Tahoma", 0, 10));
jLabel4.setText("Supercred Promotora de Vendas Ltda");
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(37, 37, 37)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 58, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jTextField1, javax.swing.GroupLayout.DEFAULT_SIZE, 234, Short.MAX_VALUE))
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, 297, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel3)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jButton2))
.addComponent(jTextField2, javax.swing.GroupLayout.DEFAULT_SIZE, 233, Short.MAX_VALUE))))
.addGap(69, 69, 69))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(255, Short.MAX_VALUE)
.addComponent(jLabel4))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1)
.addComponent(jButton2))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel4))
);
pack();
}// </editor-fold>//GEN-END:initComponents
private void jComboBox1ItemStateChanged(java.awt.event.ItemEvent evt) {//GEN-FIRST:event_jComboBox1ItemStateChanged
if (evt.getStateChange() == ItemEvent.SELECTED ){//jComboBox1.getItemCount() > -1) {
System.out.println("Item Selecionado: " + jComboBox1.getSelectedItem());
getDadosCliente();
}
}//GEN-LAST:event_jComboBox1ItemStateChanged
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
String sqlupdate = "UPDATE cliente SET nome_cliente='" + jTextField2.getText() + "' WHERE cod_cliente=" + jTextField1.getText();
con_cli.conecta();
con_cli.executeUpdate(sqlupdate);
con_cli.desconecta();
setComboClientes();
}//GEN-LAST:event_jButton1ActionPerformed
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton2ActionPerformed
this.dispose();
}//GEN-LAST:event_jButton2ActionPerformed
// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JComboBox jComboBox1;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextField jTextField2;
// End of variables declaration//GEN-END:variables
private void setComboClientes(){
jComboBox1.removeAllItems();
con_cli.conecta();
con_cli.executeSQL("SELECT * FROM cliente ORDER BY nome_cliente");
try {
while (con_cli.resultset.next()){
jComboBox1.addItem(con_cli.resultset.getString("cod_cliente") + " - " + con_cli.resultset.getString("nome_cliente"));
}
} catch (SQLException ex) {
ex.printStackTrace();
}
con_cli.desconecta();
}
private void setLookAndFeel() {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
SwingUtilities.updateComponentTreeUI(this);
this.pack();
} catch (ClassNotFoundException ex) {
JOptionPane.showMessageDialog(this, ex);
} catch (InstantiationException ex) {
JOptionPane.showMessageDialog(this, ex);
} catch (IllegalAccessException ex) {
JOptionPane.showMessageDialog(this, ex);
} catch (UnsupportedLookAndFeelException ex) {
JOptionPane.showMessageDialog(this, ex);
}
}
private void getDadosCliente() {
//O método split separa a string selecionada do jComboBox por um separador, no caso " - "
//Abaixo, criei um array que recebe do método split os itens em cada posição
String itensSemSeparador[] = jComboBox1.getSelectedItem().toString().split(" - ");
//pega o primeiro valor do array e exibe no jTextField
jTextField1.setText(itensSemSeparador[0]);
//pega o segundo valor do array e exibe no jTextField
jTextField2.setText(itensSemSeparador[1]);
}
private void setAparencia() {
//método que troca o lookAndFell deste JFrame
//LookAndFeel é a aparencia dos botões e janelas usada pelo gerenciador de janelas swing
setLookAndFeel();
//Modifica o tÃtulo da janela
setTitle("Consulta Clientes(Alteração))");
//Modifica a dica para o botão quando passa o mouse sobre ele
jButton1.setToolTipText("Altere o nome do cliente selecionado na no box acima e clique aqui(alterar) para alterar!");
}
}