package presentacion;

import java.util.*;
import entidad.Persona;
import javax.swing.JOptionPane;
import javax.swing.table.DefaultTableModel;
import negocio.NegPersona;

public class VentanaInformePersona extends javax.swing.JFrame {

    List<Persona> personas;
   
    public VentanaInformePersona() {
        initComponents();
    }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        jScrollPane1 = new javax.swing.JScrollPane();
        tblPersona = new javax.swing.JTable();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        addWindowListener(new java.awt.event.WindowAdapter() {
            public void windowOpened(java.awt.event.WindowEvent evt) {
             &n bsp;  formWindowOpened(evt);
            }
        });

        tblPersona.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {

            },
            new String [] {
             &n bsp;  "RUT", "NOMBRE"
            }
        ));
        jScrollPane1.setViewportView(tblPersona);

     &nbs p;  javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
             &n bsp;  .addContainerGap()
             &n bsp;  .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 239, javax.swing.GroupLayout.PREFERRED_SIZE)
             &n bsp;  .addContainerGap(58, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
             &n bsp;  .addContainerGap()
             &n bsp;  .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 179, javax.swing.GroupLayout.PREFERRED_SIZE)
             &n bsp;  .addContainerGap(58, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>

    private void formWindowOpened(java.awt.event.WindowEvent evt) {
        NegPersona nPer = new NegPersona();
        try{
            this.personas = nPer.getAllPersona();
        } catch (Exception e) {
            JOptionPane.showMessageDialog(rootPane, "Error");
        }
        DefaultTableModel tModel = (DefaultTableModel)this.tblPersona.getModel();
        tModel.setRowCount(0);
        for(Persona p : this.personas) {
            tModel.addRow(new Object[]{p.getRut(),p.getNombre()});
        }
    }

    public static void main(String args[]) {

        //<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()) {
             &n bsp;  if ("Nimbus".equals(info.getName())) {
             &n bsp;      javax.swing.UIManager.setLookAndFeel(info.getClassName());
             &n bsp;      break;
             &n bsp;  }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(VentanaInformePersona.class.getName()).log(java.u til.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(VentanaInformePersona.class.getName()).log(java.u til.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(VentanaInformePersona.class.getName()).log(java.u til.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(VentanaInformePersona.class.getName()).log(java.u til.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
             &n bsp;  new VentanaInformePersona().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable tblPersona;
    // End of variables declaration
}

Ejercicio

Crear un arreglo multimensional dinamico con 2 listas que tenga 10 numeros aleatorios, y luego sumar los 3 primeros elementos de cada lista como resultado.

package proyectomulti;

import java.util.ArrayList;
import java.util.List;

public class Main {

    public static void main(String[] args) {
        List<List<Integer>> contenedor = new ArrayList();
        contenedor.add(generaNumero(10));
        contenedor.add(generaNumero(10));
        double acum = 0;
        for(List<Integer> lista : contenedor) {
            acum = acum + lista.get(0) + lista.get(1) + lista.get(2);
        }
        System.out.println("Suma es : " + acum);
    }
   
    public static List<Integer> generaNumero(int cantidad) {
        List<Integer> enteros = new ArrayList();
        for(int i=1; i<=cantidad; i++) {
            int num = (int)Math.floor(Math.random()*8 + 8);       
            enteros.add(num);
        }
        return enteros;
    }
}