bonjour j'est un probleme , je travaille sur une application est je voudrais en click sur une button le fenêtre se redimention est safiche un jtable ,le probleme c'est que le jtable ne s affiche pas ,mais lorsque je redimension manuel le jtable saffiche
if(o==">>>"){bre.setText("<<<");setSize(700,300); }
else{bre.setText(">>>");setSize(300,300);}
merci

Réponse acceptée !
C'est mieux de faire la comparaison comme ceci:
if (o.equals(">>>")) {
As-tu essayé avec validate(), respectivement revalidate() et/ou repaint()  ?

merci pour la réponse mais je suis pas comment faire ????????

voila mon application je voudrais en click sur le button (>>>) le jtable apparu

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;
class monproje extends JFrame {
JTextField tnom=new JTextField();
JTextField tprenom=new JTextField();
JTextField tage=new JTextField();
JTextField ttelephone=new JTextField();
JButton bok=new JButton("ajout"); 
JButton ben=new JButton("enregistre");
JButton bch=new JButton("cherche"); 
JButton bre=new JButton(">>>");
JLabel lnom=new JLabel("nom :");
JLabel lprenom=new JLabel("prenom :");
JLabel lage=new JLabel("age :");
JLabel ltelephone=new JLabel("telephone :");
          JPanel panel=new JPanel();
JPanel panel2=new JPanel();
public monproje(){
 
  super("employe");
 
 setSize(300,300);
  H h=new H(); bok.addActionListener(h);
  Ha hz=new Ha(); ben.addActionListener(hz);
  Hch ch=new Hch(); bch.addActionListener(ch);
  Hre re=new Hre(); bre.addActionListener(re);
 
add(bre);add(bch);add(bok); add(lnom);add(lprenom);add(lage);add(ltelephone);add(ben);
    add(tnom);add(tprenom);add(tage);add(ttelephone);
   bok.setBounds(60,160,80,20);ben.setBounds(160,160,95,20);bch.setBounds(100,190,90,20);bre.setBounds(230,240,60,20);
lnom.setBounds(30,20,50,20); tnom.setBounds(130,20,80,20);
lprenom.setBounds(30,50,60,20);tprenom.setBounds(130,50,80,20);
lage.setBounds(30,80,30,20);tage.setBounds(130,80,40,20);;
ltelephone.setBounds(30,110,70,30);ttelephone.setBounds(130,110,70,20); 
       String[] columnNames = {"Nom","Prenom","Age","Telephone"};
     Object[][] data = {    };
       
        final JTable table = new JTable(data, columnNames);
           
                  JScrollPane scrollPane = new JScrollPane(table);
 
panel.setBackground(Color.blue);
               panel.add(scrollPane);
panel.setBounds(300,10,455,100);
add(panel);
           add(panel2);
         } 
 ///////////////////////////main////////////////////////////
  public static void main(String[]args){
  SwingUtilities.invokeLater(new Runnable() {    public void run() { } });
  
 monproje p=new monproje();
  p.setVisible(true);
  
 }public void ecrire()throws IOException{
 try {
   
    ObjectInputStream entree = new ObjectInputStream(new FileInputStream("a.txt"));
  employe personnel[] = (employe[]) entree.readObject();
  entree.close();
                                
  for (int i=0;i<personnel.length;i++) {
  personnel[i].toString();
  
 }
    }
    catch (Exception ex) {
    }

            }
               private class Hre implements ActionListener {
   public void actionPerformed(ActionEvent evt) {

String o;
o=bre.getText();
if(o==">>>"){bre.setText("<<<");setSize(700,300); }
else{bre.setText(">>>");setSize(300,300);}
        }
  
 }
   private class H implements ActionListener {
   public void actionPerformed(ActionEvent evt) {
  ajoute();
        }
  
 }
    private class Ha implements ActionListener {
   public void actionPerformed(ActionEvent evt) {
  enregistre();
        }
    }
    private class Hch implements ActionListener {
   public void actionPerformed(ActionEvent evt) {
  r();
        }
    } 
    Vector v=new Vector();
 public void ajoute(){
 if(tnom.getText().length()==0||tprenom.getText().length()==0||tage.getText().length()==0||ttelephone.getText().length()==0){
          JOptionPane.showMessageDialog(null,"un ou plusieur champ son vide","erreur",JOptionPane.ERROR_MESSAGE);
 }
 else{
 
 employe ee=new employe(tnom.getText(),tprenom.getText(),tage.getText(),ttelephone.getText());
          v.add(ee);
            tnom.setText(""); tprenom.setText("");
              ttelephone.setText(""); tage.setText("");
     JOptionPane.showMessageDialog(null,"l'employe est enregistre");
     }
     }
     public void enregistre() {
      try {
        PrintWriter f = new PrintWriter(new FileWriter("a.txt"));
      f.print(v);
      f.close();
        JOptionPane.showMessageDialog(null,"enregistre");
      }
      catch (Exception ex) {
       System.out.println ("a");
      }
     
     }
     public  void r(){
      String ch ;

ch=JOptionPane.showInputDialog("entrez le nom que vous voules cherche");
boolean a=false;
for(int i=0;i<v.size();i++){
    if(((employe)v.get(i)).getNom().equals(ch)){
     a=true;
 tprenom.setText(((employe)v.get(i)).getPrenom());
        tnom.setText(((employe)v.get(i)).getNom());
tage.setText(((employe)v.get(i)).getAge());
    ttelephone.setText(((employe)v.get(i)).getTelephone());
    }  }
    if(a==false){
        JOptionPane.showMessageDialog(null,"se nom n'est pas enregistre");
    }

     }
}

 

 
   
   
  
  

Réponse acceptée !
Le positionnement avec setBounds n'est pas conseillé. Apprends à utiliser les LayoutManager. Voici un exemple avec GridBagLayout:
package test;
/*
 * FenetreEmploye.java
 */

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;

class FenetreEmploye extends JFrame {

    private JTextField tnom = new JTextField();
    private JTextField tprenom = new JTextField();
    private JTextField tage = new JTextField();
    private JTextField ttelephone = new JTextField();
    private JButton btAjoute = new JButton("ajout");
    private JButton btEnregistre = new JButton("enregistre");
    private JButton btRecherche = new JButton("cherche");
    private JButton btResize = new JButton(">>>");
    private JLabel lnom = new JLabel("nom :");
    private JLabel lprenom = new JLabel("prenom :");
    private JLabel lage = new JLabel("age :");
    private JLabel ltelephone = new JLabel("telephone :");
    private JTable table;
    private JScrollPane scrollPane;

    public FenetreEmploye() {
        super("Employe");
        java.awt.GridBagConstraints gridBagConstraints;
        lnom.setPreferredSize(new Dimension(70, 20));
        lprenom.setPreferredSize(new Dimension(70, 20));
        lage.setPreferredSize(new Dimension(70, 20));
        ltelephone.setPreferredSize(new Dimension(70, 20));
        tnom.setPreferredSize(new Dimension(70, 20));
        tprenom.setPreferredSize(new Dimension(70, 20));
        tage.setPreferredSize(new Dimension(70, 20));
        ttelephone.setPreferredSize(new Dimension(70, 20));

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        getContentPane().setLayout(new java.awt.GridBagLayout());

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(lnom, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(tnom, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(lprenom, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(tprenom, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(lage, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(tage, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 3;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(ltelephone, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 3;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(ttelephone, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 4;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(btAjoute, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 4;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(btEnregistre, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 2;
        gridBagConstraints.gridy = 4;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(btRecherche, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 2;
        gridBagConstraints.gridy = 5;
        gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5);
        getContentPane().add(btResize, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 3;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridheight = 6;
        String[] columnNames = {"Nom", "Prenom", "Age", "Telephone"};
        Object[][] data = {};
        table = new JTable(data, columnNames);
        table.setPreferredScrollableViewportSize(new Dimension(400, 150));
        scrollPane = new JScrollPane(table);
        getContentPane().add(scrollPane, gridBagConstraints);
        scrollPane.setVisible(false);
        pack();

        ActionAjoute actionAjoute = new ActionAjoute();
        btAjoute.addActionListener(actionAjoute);
        ActionEnregistre actionEnregistre = new ActionEnregistre();
        btEnregistre.addActionListener(actionEnregistre);
        ActionRecherche actionRecherche = new ActionRecherche();
        btRecherche.addActionListener(actionRecherche);
        ActionResize actionResize = new ActionResize();
        btResize.addActionListener(actionResize);
       
    }
    ///////////////////////////main////////////////////////////
    public static void main(final String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new FenetreEmploye().setVisible(true);
            }
        });
    }

    public void ecrire() throws IOException {
        try {

            ObjectInputStream entree = new ObjectInputStream(new FileInputStream("a.txt"));
            Employe[] personnel = (Employe[]) entree.readObject();
            entree.close();

            for (int i = 0; i < personnel.length; i++) {
                personnel[i].toString();

            }
        } catch (Exception ex) {
        }

    }

    private class ActionResize implements ActionListener {

        @Override
        public void actionPerformed(final ActionEvent evt) {
            String o;
            o = btResize.getText();
            if (o.equals(">>>")) {
                scrollPane.setVisible(true);
                btResize.setText("<<<");
                pack();
            } else {
                scrollPane.setVisible(false);
                btResize.setText(">>>");
                pack();
            }
        }
    }

    private class ActionAjoute implements ActionListener {

        @Override
        public void actionPerformed(final ActionEvent evt) {
            ajoute();
        }
    }

    private class ActionEnregistre implements ActionListener {

        @Override
        public void actionPerformed(final ActionEvent evt) {
            enregistre();
        }
    }

    private class ActionRecherche implements ActionListener {

        @Override
        public void actionPerformed(final ActionEvent evt) {
            recherche();
        }
    }
    Vector v = new Vector();

    public void ajoute() {
        if (tnom.getText().length() == 0 || tprenom.getText().length() == 0 || tage.getText().length() == 0 || ttelephone.getText().length() == 0) {
            JOptionPane.showMessageDialog(null, "un ou plusieur champ son vide", "erreur", JOptionPane.ERROR_MESSAGE);
        } else {

            Employe ee = new Employe(tnom.getText(), tprenom.getText(), tage.getText(), ttelephone.getText());
            v.add(ee);
            tnom.setText("");
            tprenom.setText("");
            ttelephone.setText("");
            tage.setText("");
            JOptionPane.showMessageDialog(null, "l'employe est enregistre");
        }
    }

    public void enregistre() {
        try {
            PrintWriter f = new PrintWriter(new FileWriter("a.txt"));
            f.print(v);
            f.close();
            JOptionPane.showMessageDialog(null, "enregistre");
        } catch (Exception ex) {
            System.out.println("a");
        }

    }

    public void recherche() {
        String nomRecherche;
        nomRecherche = JOptionPane.showInputDialog("entrez le nom que vous voulez chercher");
        boolean a = false;
        for (int i = 0; i < v.size(); i++) {
            if (((Employe) v.get(i)).getNom().equals(nomRecherche)) {
                a = true;
                tprenom.setText(((Employe) v.get(i)).getPrenom());
                tnom.setText(((Employe) v.get(i)).getNom());
                tage.setText(((Employe) v.get(i)).getAge());
                ttelephone.setText(((Employe) v.get(i)).getTelephone());
            }
        }
        if (a == false) {
            JOptionPane.showMessageDialog(null, "ce nom n'est pas enregistre");
        }

    }
}

class Employe {

    private String nom;
    private String prenom;
    private String age;
    private String telephone;

    Employe(final String nom, final String prenom, final String age, final String telephone) {
        this.nom = nom;
        this.prenom = prenom;
        this.age = age;
        this.telephone = telephone;
    }

    public String getAge() {
        return age;
    }

    public String getNom() {
        return nom;
    }

    public String getPrenom() {
        return prenom;
    }

    public String getTelephone() {
        return telephone;
    }
}

merci pour le code ,je veux recuperer les information du fichier dans les execution  de l'application(load)

Réponse acceptée !
Voici un exemple avec XMLEncoder/XMLDencoder: EmployeDemo.jar (code source dans le jar)

merci pour le code ,mais est ce que vous pouvez me donner le code source de cette aplication( EmployeDemo.jar )

Attention! Il faut bien lire

dsl pour le derangement mais le code source s'execute pas
si vous pouvez me lancer  le fichier .java :)
merci d avance