Passando uma String para MD5

Ola galera sou leigo ainda em desenvolvimento em Java gostaria de uma ajuda como faço pra salvar uma String em md5....

package AutoProgram;

import br.ifirst.autosystem.connections.Conexao;
import br.ifirst.autosystem.connections.ConfigDataBase;
import br.ifirst.autosystem.entidades.Usuario;
import br.ifirst.autosystem.exceptions.ArquivoConfigException;
import br.ifirst.autosystem.operacoes.UsuarioOperacao;
import java.awt.event.KeyEvent;
import java.sql.SQLException;
import javax.swing.JOptionPane;

public class Login extends javax.swing.JFrame {

String usuario, senha;
    int cod;

private void buscaUsuario(){
        if (!txtUsu.getText().equals("")){
            cod = Integer.parseInt(txtUsu.getText());
            
        Usuario u;
            
        u = UsuarioOperacao.getNmUsuario(cod);
        
        if (u == null){
            JOptionPane.showMessageDialog(null, "Usuário não encontrado!");
            limparUsu();
            return;
        }
        txtNome.setText(u.getNmUsu());
    }
   }
   private void limparUsu(){
            txtUsu.setText("");
            txtNome.setText("");
            txtSenha.setText("");
            labelinforme.setText("");
   }
        
    public Login() {
        initComponents();
        setLocationRelativeTo(null);
        
        try {
            Conexao.getConnection();
        } catch (SQLException ex) {
            
        } catch (ArquivoConfigException ex) {
            new ConfigDataBase().setVisible(true);
        }
    }

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

jPanel1 = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        txtUsu = new javax.swing.JTextField();
        txtSenha = new javax.swing.JPasswordField();
        butLogin = new javax.swing.JButton();
        butSair = new javax.swing.JButton();
        labelinforme = new javax.swing.JLabel();
        txtNome = new javax.swing.JTextField();
        jLabel3 = new javax.swing.JLabel();

setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
        setTitle("Login");
        setLocationByPlatform(true);
        setResizable(false);

jPanel1.setBackground(new java.awt.Color(255, 255, 255));
        jPanel1.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));

jLabel1.setFont(new java.awt.Font("Times New Roman", 1, 12));
        jLabel1.setText("Cód. Usuario:");

jLabel2.setFont(new java.awt.Font("Times New Roman", 1, 12));
        jLabel2.setText("Senha :");

txtUsu.setFont(new java.awt.Font("Trebuchet MS", 0, 16)); // NOI18N
        txtUsu.setHorizontalAlignment(javax.swing.JTextField.RIGHT);
        txtUsu.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                txtUsuActionPerformed(evt);
            }
        });
        txtUsu.addFocusListener(new java.awt.event.FocusAdapter() {
            public void focusLost(java.awt.event.FocusEvent evt) {
                txtUsuFocusLost(evt);
            }
        });
        txtUsu.addKeyListener(new java.awt.event.KeyAdapter() {
            public void keyPressed(java.awt.event.KeyEvent evt) {
                txtUsuKeyPressed(evt);
            }
        });

txtSenha.setFont(new java.awt.Font("Trebuchet MS", 0, 16)); // NOI18N
        txtSenha.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                txtSenhaActionPerformed(evt);
            }
        });

butLogin.setFont(new java.awt.Font("Times New Roman", 0, 12)); // NOI18N
        butLogin.setIcon(new javax.swing.ImageIcon(getClass().getResource("/br/ifirst/autosystem/resources/login.png"))); // NOI18N
        butLogin.setText("Login");
        butLogin.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                butLoginActionPerformed(evt);
            }
        });

butSair.setFont(new java.awt.Font("Times New Roman", 0, 11));
        butSair.setIcon(new javax.swing.ImageIcon(getClass().getResource("/br/ifirst/autosystem/resources/sair.png"))); // NOI18N
        butSair.setText("Sair");
        butSair.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                butSairActionPerformed(evt);
            }
        });

txtNome.setEditable(false);
        txtNome.setFont(new java.awt.Font("Trebuchet MS", 0, 16)); // NOI18N

jLabel3.setFont(new java.awt.Font("Times New Roman", 1, 12));
        jLabel3.setText("Nome :");

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()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(jLabel1)
                            .addComponent(jLabel2))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addComponent(txtUsu, javax.swing.GroupLayout.PREFERRED_SIZE, 69, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                                .addComponent(jLabel3)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(txtNome, javax.swing.GroupLayout.PREFERRED_SIZE, 193, javax.swing.GroupLayout.PREFERRED_SIZE))
                            .addComponent(txtSenha, javax.swing.GroupLayout.PREFERRED_SIZE, 152, javax.swing.GroupLayout.PREFERRED_SIZE)))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addComponent(labelinforme, javax.swing.GroupLayout.PREFERRED_SIZE, 237, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 58, Short.MAX_VALUE))
                            .addComponent(butLogin))
                        .addComponent(butSair)))
                .addContainerGap())
        );

jPanel1Layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {butLogin, butSair});

jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel1)
                    .addComponent(txtUsu, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(txtNome, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel3))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(txtSenha, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(11, 11, 11)
                .addComponent(labelinforme, javax.swing.GroupLayout.PREFERRED_SIZE, 12, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(butLogin)
                    .addComponent(butSair, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap())
        );

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        );

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

private void butSairActionPerformed(java.awt.event.ActionEvent evt) {                                        
            System.exit(0);
        }

private void butLoginActionPerformed(java.awt.event.ActionEvent evt) {                                         
            usuario = txtUsu.getText();
            senha = txtSenha.getText();
            Usuario u = new Usuario();
            u.setId(Long.parseLong(usuario));
            u.setSenha(String.valueOf(senha));

if (UsuarioOperacao.validaLogin(u)) {
                UsuarioLogado.setUsuario(UsuarioOperacao.getUsuario(u));
                new AutoSystem().setVisible(true);
                this.dispose();
            } else {
                labelinforme.setText("Usuario ou senha invalido");
            }
        }

private void txtSenhaActionPerformed(java.awt.event.ActionEvent evt) {                                         
            usuario = txtUsu.getText();
            senha = txtSenha.getText();
            Usuario u = new Usuario();
            u.setId(Long.parseLong(usuario));
            u.setSenha(String.valueOf(senha));

if (UsuarioOperacao.validaLogin(u)) {
                UsuarioLogado.setUsuario(UsuarioOperacao.getUsuario(u));
                new AutoSystem().setVisible(true);
                this.dispose();
            } 
            else {
                labelinforme.setText("Usuario ou senha invalido");
            }
        }

private void txtUsuActionPerformed(java.awt.event.ActionEvent evt) {                                       
        
    }

private void txtUsuKeyPressed(java.awt.event.KeyEvent evt) {                                  
        if (evt.getKeyCode() == KeyEvent.VK_ENTER){
            buscaUsuario();
        }
    }

private void txtUsuFocusLost(java.awt.event.FocusEvent evt) {                                 
        buscaUsuario();
    }

JavaBaby Membro desde: 07/06/2011 23:39:02 Mensagens: 99 Offline

No GUJ já tem um artigo interessante sobre o que você deseja: http://www.guj.com.br/articles/32

Você também pode usar a biblioteca Apache Commons Codec, que já tem os métodos prontos.
Para ser mais específico, a classe DigestUtils possui os métodos que você deseja.

Notícias, artigos e o maior fórum brasileiro sobre Java