Rafael, muito obrigado pela ajuda, mas ainda estou tendo erros, criei duas classes: a BancoDeDados, que se conecta no banco e executa as queries, e a frameLogin, onde o usuario preenche seu login e senha, vou colar os codigos aqui:
============== CLASSE BancoDeDados ================
import java.sql.*;
public class BancoDeDados {
private Connection con;
private Boolean valida;
public void getConnection() {
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost/inventario","admin","12345");
}
catch(Exception e) {
e.printStackTrace();
}
}
public Boolean setValidacao(String query, String login, String pass) {
try {
Statement stmt = con.createStatement();
ResultSet res = stmt.executeQuery(query);
while (res.next()) {
String nome = res.getString("user");
String senha = res.getString("pass");
if (nome == login && senha == pass)
valida = true;
}
}
catch (Exception e) {
e.printStackTrace();
}
return valida;
}
}
============CLASSE frameLogin=====================
import javax.swing.*;
public class frameLogin extends javax.swing.JFrame {
/** Creates new form frameLogin */
public frameLogin() {
initComponents();
objConexao = new BancoDeDados();
}
(...)
private void botaoLoginActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String login = campoLogin.getText();
String senha = campoSenha.getText();
objConexao.getConnection();
Boolean valida = objConexao.setValidacao("SELECT user,pass FROM login WHERE user = \""+login+"\" AND pass =\""+senha+"\";",login,senha);
if (valida == true)
JOptionPane.showMessageDialog(null,"Usuário Validado com sucesso");
else
JOptionPane.showMessageDialog(null,"Os dados informados estão incorretos");
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new frameLogin().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton botaoLogin;
private javax.swing.JLabel cabecalho;
private javax.swing.JTextField campoLogin;
private javax.swing.JPasswordField campoSenha;
private javax.swing.JLabel labelLogin;
private javax.swing.JLabel labelSenha;
private javax.swing.JPanel mensagem;
// End of variables declaration
private BancoDeDados objConexao;
}
O programa roda, consigo preencher o nome de usuario e senha, mas quando aperto no botão para validar aparece:
Exception in thread “AWT-EventQueue-0” java.lang.NullPointerException
at frameLogin.botaoLoginActionPerformed(frameLogin.java:121)
at frameLogin.access$000(frameLogin.java:12)
at frameLogin$1.actionPerformed(frameLogin.java:50)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1849)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2169)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:234)
at java.awt.Component.processMouseEvent(Component.java:5488)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3093)
at java.awt.Component.processEvent(Component.java:5253)
at java.awt.Container.processEvent(Container.java:1966)
at java.awt.Component.dispatchEventImpl(Component.java:3955)
at java.awt.Container.dispatchEventImpl(Container.java:2024)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3892)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
at java.awt.Container.dispatchEventImpl(Container.java:2010)
at java.awt.Window.dispatchEventImpl(Window.java:1766)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:234)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
BUILD SUCCESSFUL (total time: 10 seconds)
Gostaria de saber onde está o erro, abraços.
[color=“red”]Favor colocar códigos entre as tags (code)(/code)* - Reifel.