Augmenter la taille d'un tableau

for (Object o : liste)
    System.out.println(o);

import java.util.ArrayList;

   public class ArrayListDemo
   {
      public static void main(String[] args)
      {
         ArrayList<Object> arrL = new ArrayList<Object>();
         
         ArrayList<String> t3 = new ArrayList<String>(); 
    	
         t3.add ("Bonjour");
         t3.add ("Salut");
         t3.add ("xyz");
         t3.add ("salut");
         t3.add ("Salut");
      
      	
         System.out.println("\nContenu de t3: " + t3);
         //ou bien comme un tableau "classique":
         if(t3.size() >0) // noter .size() et non .length()
         {
            for(int i=0;i<t3.size();i++)
            {
               System.out.println("item " + i + ": " + t3.get(i) + "\n");
            }
         }
         else System.out.println("t3 est vide !!!...");
         
         
         Integer i1 = new Integer(10);
         Integer i2 = new Integer(20);
         Integer i3 = new Integer(30);
         Integer i4 = new Integer(40);
         String str = "Salut";
         
         System.out.println("\nContenu initial de arrL: " + arrL);
         System.out.println("Taille de arrL: " + arrL.size() + "\n");
         
         System.out.println("On ajoute les 3 premiers items:\n"
            + "-i1: " + i1 + "\n"
            + "-i2: " + i2 + "\n"
            + "-str: \"" + str + "\"");
         
      	//ajout des 3 élements
      	
         arrL.add(i1);
         arrL.add(i2);
         arrL.add(str);
         
         System.out.println("\nNouveau contenu de arrL: " + arrL);
         System.out.println("Taille de arrL: " + arrL.size() + "\n");
      
      	//ajout de 6 élements dont un nouveau (i5) et encore (str)
         arrL.add(i1);
         arrL.add(i2);
         arrL.add(i3);
         arrL.add(i4);
         Integer i5 = new Integer(50);
         arrL.add(i5);
         arrL.add(str);
         
         System.out.println("On ajoute 6 items dont 2 nouveaux (i5) et encore (str):\n"
            + "-i1: " + i1 + "\n"
            + "-i2: " + i2 + "\n"
            + "-i3: " + i3 + "\n"
            + "-i4: " + i4 + "\n"
            + "-i5: " + i5 + "\n"
            + "-str: " + str + "\n");
         
         System.out.println("Nouveau contenu de arrL: " + arrL);
         System.out.println("Nouvelle taille de arrL: " + arrL.size() + "\n");
         
      	// L'autre maniere de lister le contenu de l'ArrayList arrL
      	
         System.out.println("Autre maniere de lister le contenu de l'ArrayList arrL:\n");
         for(int i=0;i<arrL.size();i++)
         {
            System.out.println("item " + i + ": " + arrL.get(i) + "\n");
         }
         
      	// Obtenir l'indice d'un item de l'ArrayList arrL
      	
         boolean trouve = false;
         Object obj;
      	
         obj = "Salut";
      // obj = 10;
         int i = 0;
         System.out.println("On recherche l'objet " + obj + ":");
         for(i=0;i<arrL.size();i++)
         {
            if(arrL.get(i).equals(obj))
            {
               System.out.println("item " + i + ": " + arrL.get(i) + ".");
               trouve = true;
            }
         }
         System.out.println("");
         if(!trouve)
            System.out.println("L'objet " + obj + " n'existe pas...\n");
      
         // Clonage de arrL avant suppression d'un élément
         Object arrLClone = arrL.clone();
         
         System.out.println("On clone arrL sous le nom arrLClone (save avant remove):");
      	  
         System.out.println("Le clone (arrLClone) de arrL est: " + arrLClone + "\n");
      
      	// Suppression  de l'élément 2 
         arrL.remove(2);
      
         System.out.println("On supprime l'item 2 de arrL:");
        
         System.out.println("Nouveau contenu de arrL: " + arrL);
         System.out.println("Nouvelle taille de arrL: " + arrL.size() + "\n");      
      }
   }

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTable;

public class Projet extends JFrame
{
	private static final long serialVersionUID = 1;

	private final JButton bouton;
	
	private final JTable table1;
	private final JTable table2;

	private final JTabbedPane tabPane;
	
	public Projet()
	{		
		// Onglet 1
		////////////
		
		JPanel jp1=new JPanel();
		
		bouton = new JButton("OK");
		bouton.addActionListener(new ActionListener () 
        { 
            @Override 
            public void actionPerformed(ActionEvent e) 
            {
                JOptionPane.showMessageDialog(null,"OK !!!"); // TODO
            } 
        });
		
		jp1.add(bouton);
		
		// Onglet 2
		////////////
		
		JPanel jp2=new JPanel();
		jp2.setLayout(new BorderLayout());
		jp2.setBackground(Color.GRAY);
		
		table1 = formaterTable("1","2","3","4","5","6");
		
		jp2.add(new JScrollPane(table1));
		
		// Onglet 3
		////////////
		
		JPanel jp3=new JPanel();
		jp3.setLayout(new BorderLayout());
		jp3.setBackground(Color.GRAY);
		
		table2 = formaterTable("1","2","3","4");
		
		jp3.add(new JScrollPane(table2));
		
		// Onglets
		///////////
		
		tabPane = new JTabbedPane();
		
		tabPane.addTab("onglet1", jp1);
		tabPane.addTab("onglet2", jp2);
		tabPane.addTab("onglet3", jp3);

		// Application
		///////////////
		
		setTitle("Une application");
		setSize(new Dimension(400,300));
		setExtendedState(MAXIMIZED_BOTH);
		
		add(tabPane);			

		setVisible(true);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	
	private JTable formaterTable(String...columnNames)
	{
		JTable table = new JTable(new Object[][] {},columnNames);
		table.setSelectionMode(1);
		table.setRowHeight(20);
		table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);
		//table.setTableHeader(null);
		table.setFillsViewportHeight(true);
		return table;
	}
	
	public static void main(String[] args)
	{
		new Projet();
	}
}

String r1[][] = new String[][] {...}, r2[][] = new String[][] {...};

table1 = formaterTable(r1,"1","2","3","4","5","6");
table2 = formaterTable(r2,"1","2","3","4");

private JTable formaterTable(Object[][] rowData, String...columnNames)
{
    JTable table = new JTable(new DefaultTableModel(rowData,columnNames));
    //...
}

private void ajouter(JTable table, Object[][] rowData)
{ 
	DefaultTableModel dtm = (DefaultTableModel) table.getModel();
	for (Object[] row : rowData)
		dtm.addRow(row);
}

private void effacer(JTable table)
{
	DefaultTableModel dtm = (DefaultTableModel) table.getModel();
	while (dtm.getRowCount()>0)
		dtm.removeRow(0);
}

Button quitter = new JButton("Quitter");
quitter.addActionListener(new ActionListener () 
{ 
    @Override 
    public void actionPerformed(ActionEvent e) 
    {
        int n = JOptionPane.showConfirmDialog(
            null,"Voulez-vous quitter ?","Quitter",JOptionPane.YES_NO_OPTION);

        switch(n)
        {
        case JOptionPane.YES_OPTION : System.exit(0);
        case JOptionPane.NO_OPTION : break;
        case JOptionPane.CLOSED_OPTION : actionPerformed(e); break;
        }
});