hola estoy trabajando en una aplicación y ya tengo el formulario conectado a la data base pero tengo que controlar que el id sea ingresado solo 1 vez a la base de datos y en caso de querer registrar ese id nuevamente me diga por pantalla en un cuadro de dialogo que ese id ya esta en la data base. package aguasdelvalle;
/**
*
* @author Usuario
*/
public class Consultar extends javax.swing.JDialog {
/**
* Creates new form Consultar
*/
public Consultar(java.awt.Frame parent, boolean modal) {
super(parent, modal);
initComponents();
}
/**
* 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() {
jPanel1 = new javax.swing.JPanel();
jLconsultarPor = new javax.swing.JLabel();
jTextField1 = new javax.swing.JTextField();
jScrollPane2 = new javax.swing.JScrollPane();
jTable1 = new javax.swing.JTable();
jComboBox1 = new javax.swing.JComboBox<>();
jButton1 = new javax.swing.JButton();
jCheckBox1 = new javax.swing.JCheckBox();
setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
jLconsultarPor.setText("Consultar Por:");
jTextField1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField1ActionPerformed(evt);
}
});
jTable1.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
{null, null, null, null, null, null, null},
{null, null, null, null, null, null, null},
{null, null, null, null, null, null, null},
{null, null, null, null, null, null, null}
},
new String [] {
"Id", "Nombres", "Apellidos", "Teléfono", "Dirección", "Cargo", "Email"
}
) {
Class[] types = new Class [] {
java.lang.Integer.class, java.lang.String.class, java.lang.String.class, java.lang.String.class, java.lang.String.class, java.lang.String.class, java.lang.String.class
};
boolean[] canEdit = new boolean [] {
false, false, false, false, false, true, true
};
public Class getColumnClass(int columnIndex) {
return types [columnIndex];
}
public boolean isCellEditable(int rowIndex, int columnIndex) {
return canEdit [columnIndex];
}
});
jScrollPane2.setViewportView(jTable1);
jComboBox1.setModel(new javax.swing.DefaultComboBoxModel<>(new String[] { "Id", "Nombre", "Apellido", "Teléfono", "Dirección", "Cargo", "Correo Eléctronico" }));
jButton1.setText("Consultar");
jCheckBox1.setText("Que contenga");
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLconsultarPor)
.addGap(18, 18, 18)
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, 99, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(25, 25, 25)
.addComponent(jCheckBox1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 89, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jButton1)
.addContainerGap(280, Short.MAX_VALUE))
.addComponent(jScrollPane2)
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(12, 12, 12)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton1)
.addComponent(jCheckBox1))
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLconsultarPor)
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(18, 18, 18)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(19, 19, 19)
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
pack();
}// </editor-fold>
private void jTextField1ActionPerformed(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(Consultar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Consultar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Consultar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Consultar.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the dialog */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
Consultar dialog = new Consultar(new javax.swing.JFrame(), true);
dialog.addWindowListener(new java.awt.event.WindowAdapter() {
@Override
public void windowClosing(java.awt.event.WindowEvent e) {
System.exit(0);
}
});
dialog.setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JCheckBox jCheckBox1;
private javax.swing.JComboBox<String> jComboBox1;
private javax.swing.JLabel jLconsultarPor;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTable jTable1;
private javax.swing.JTextField jTextField1;
// End of variables declaration
}
Hola. Pues para hacerlo utiliza una condicional.
If (id existe){
Mostrar alerta}
Else{Agregar id}
Espero sea d ayuda. No se si alguien tendría otro metodo
Deberia el ID ser autoincremental y que se maneje automaticamente desde la base de datos
Normalmente los id son generados en la capa de datos de la aplicación, en tu caso, viendo que es una aplicación monolítica debieras manejarlo del lado del modelo o entidad y no desde el input de entrada de capa de presentación. Imagina que un usuario ingrese un valor de capacidad máxima en la base de datos o exponga los identificadores para realizar ataques a la base de datos.
Tal como dice Bartz, eso debiera controlarlo la base de datos a traves de un id numérico autoincrementable y aun así ese id no debiese ser utilizado para ser mostrado al usuario final, para eso existen los UUID, de esta manera un usuario nunca sabrá la cantidad de registros o intentar modificar el identificador para visualizar datos que no debiera tener acceso:
https://www.baeldung.com/java-uuid
https://es.wikipedia.org/wiki/Identificador_%C3%BAnico_universal