Classe JFilePicker em Jframe

public class JFilePicker extends JPanel {
private final String textFieldLabel;
private final String buttonLabel;
private final JLabel label;
private final JTextField textField;
private final JButton button;
private final JFileChooser fileChooser;

private int mode;
public static final int MODE_OPEN = 1;
public static final int MODE_SAVE = 2;

public JFilePicker(String textFieldLabel, String buttonLabel) {
	this.textFieldLabel = textFieldLabel;
	this.buttonLabel = buttonLabel;
	fileChooser = new JFileChooser();
	setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
	label = new JLabel(textFieldLabel);
	textField = new JTextField(30);
	button = new JButton(buttonLabel);
	button.addActionListener((ActionEvent evt) -> {
                buttonActionPerformed(evt);
            });
	add(label);
	add(textField);
	add(button);
}

private void buttonActionPerformed(ActionEvent evt) {
	if (mode == MODE_OPEN) {
		if (fileChooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
			textField.setText(fileChooser.getSelectedFile().getAbsolutePath());
		}
	} else if (mode == MODE_SAVE) {
		if (fileChooser.showSaveDialog(this) == JFileChooser.APPROVE_OPTION) {
			textField.setText(fileChooser.getSelectedFile().getAbsolutePath());
		}
	}
}

public void addFileTypeFilter(String extension, String description) {
	FileTypeFilter filter = new FileTypeFilter(extension, description);
	fileChooser.addChoosableFileFilter(filter);
}

public void setMode(int mode) {
	this.mode = mode;
}

public String getSelectedFilePath() {
	return textField.getText();
}

public JFileChooser getFileChooser() {
	return this.fileChooser;
}

public class EmailSenderForm extends javax.swing.JFrame {

private final ConfigUtility configUtil = new ConfigUtility();
private final JFilePicker filePicker = new JFilePicker("Anexo", "Anexar...");

public EmailSenderForm() throws IOException {
    initComponents();
    setLocationRelativeTo(null);
    String imagePath = "/img/email_32_32.png";
    InputStream imgStream = Entrada.class.getResourceAsStream(imagePath);
    BufferedImage myImg = ImageIO.read(imgStream);
    setIconImage(myImg);
}

private boolean validarCampos() {
    if (fieldTo.getText().equals("")) {
        JOptionPane.showMessageDialog(this,
                "Introduza o destinatário!",
                "Error", JOptionPane.ERROR_MESSAGE);
        fieldTo.requestFocus();
        return false;
    }

    if (fieldSubject.getText().equals("")) {
        JOptionPane.showMessageDialog(this,
                "Introduza o assunto deste email!",
                "Error", JOptionPane.ERROR_MESSAGE);
        fieldSubject.requestFocus();
        return false;
    }

    if (textAreaMessage.getText().equals("")) {
        JOptionPane.showMessageDialog(this,
                "Introduza a sua mensagem!",
                "Error", JOptionPane.ERROR_MESSAGE);
        textAreaMessage.requestFocus();
        return false;
    }

    return true;
}

/**
 * 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() {

    labelPara = new javax.swing.JLabel();
    labelAssunto = new javax.swing.JLabel();
    labelAnexo = new javax.swing.JLabel();
    fieldTo = new javax.swing.JTextField();
    fieldSubject = new javax.swing.JTextField();
    fieldAnexo = new javax.swing.JTextField();
    sendEmail = new javax.swing.JButton();
    pesquisarBt = new javax.swing.JButton();
    jScrollPane1 = new javax.swing.JScrollPane();
    textAreaMessage = new javax.swing.JTextArea();
    jMenuBar1 = new javax.swing.JMenuBar();
    menuPrincipal = new javax.swing.JMenu();
    menuItemTools = new javax.swing.JMenuItem();
    menuItemExit = new javax.swing.JMenuItem();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    setTitle("Envio de Email");
    setPreferredSize(new java.awt.Dimension(500, 350));

    labelPara.setFont(new java.awt.Font("Tahoma", 1, 16)); // NOI18N
    labelPara.setText("Para:");

    labelAssunto.setFont(new java.awt.Font("Tahoma", 1, 16)); // NOI18N
    labelAssunto.setText("Assunto:");

    labelAnexo.setFont(new java.awt.Font("Tahoma", 1, 16)); // NOI18N
    labelAnexo.setText("Anexo:");

    sendEmail.setIcon(new javax.swing.ImageIcon("C:\\Users\\gilca\\Documents\\NetBeansProjects\\gmc.esmaior\\src\\main\\resources\\img\\email_32_32.png")); // NOI18N
    sendEmail.setToolTipText("Enviar");
    sendEmail.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            sendEmailActionPerformed(evt);
        }
    });

    pesquisarBt.setIcon(new javax.swing.ImageIcon("C:\\Users\\gilca\\Documents\\NetBeansProjects\\gmc.esmaior\\src\\main\\resources\\img\\attach_32_32.png")); // NOI18N
    pesquisarBt.setToolTipText("Anexo");
    pesquisarBt.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            pesquisarBtActionPerformed(evt);
        }
    });

    textAreaMessage.setColumns(20);
    textAreaMessage.setRows(5);
    jScrollPane1.setViewportView(textAreaMessage);

    menuPrincipal.setText("Ferramentas");

    menuItemTools.setText("Definições Conta");
    menuPrincipal.add(menuItemTools);

    menuItemExit.setText("Sair");
    menuPrincipal.add(menuItemExit);

    jMenuBar1.add(menuPrincipal);

    setJMenuBar(jMenuBar1);

    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()
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addComponent(jScrollPane1)
                .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(labelPara)
                        .addComponent(labelAssunto)
                        .addComponent(labelAnexo))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                            .addComponent(fieldTo, javax.swing.GroupLayout.PREFERRED_SIZE, 303, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addGap(18, 18, 18))
                        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                                .addComponent(fieldAnexo)
                                .addComponent(fieldSubject, javax.swing.GroupLayout.PREFERRED_SIZE, 305, javax.swing.GroupLayout.PREFERRED_SIZE))
                            .addGap(18, 18, 18)))
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(sendEmail, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 69, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(pesquisarBt, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 71, javax.swing.GroupLayout.PREFERRED_SIZE))))
            .addContainerGap())
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                .addGroup(layout.createSequentialGroup()
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(labelPara)
                        .addComponent(fieldTo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(labelAssunto)
                        .addComponent(fieldSubject, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addComponent(sendEmail, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(layout.createSequentialGroup()
                    .addGap(18, 18, 18)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(labelAnexo)
                        .addComponent(fieldAnexo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addGroup(layout.createSequentialGroup()
                    .addGap(9, 9, 9)
                    .addComponent(pesquisarBt)))
            .addGap(18, 18, 18)
            .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 151, Short.MAX_VALUE)
            .addContainerGap())
    );

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

private void sendEmailActionPerformed(java.awt.event.ActionEvent evt) {                                          
    File[] attachFiles = null;
    if (!validarCampos()) {
        return;
    }
    String toAddress = fieldTo.getText();
    String subject = fieldSubject.getText();
    String message = textAreaMessage.getText();
    if (!filePicker.getSelectedFilePath().equals("")) {
        File selectedFile = new File(filePicker.getSelectedFilePath());
        attachFiles = new File[]{selectedFile};
    }
    try {
        Properties smtpProperties = configUtil.loadProperties();
        EmailUtility.sendEmail(smtpProperties, toAddress, subject, message, attachFiles);
        JOptionPane.showMessageDialog(this, "O e-mail foi enviado com suesso!");

    } catch (IOException | MessagingException | HeadlessException ex) {
        JOptionPane.showMessageDialog(this, "Erro no envio deste email, tente mais tarde: " + ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
    }
}                                         

private void pesquisarBtActionPerformed(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(EmailSenderForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(EmailSenderForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(EmailSenderForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(EmailSenderForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(() -> {
        try {
            new EmailSenderForm().setVisible(true);
        } catch (IOException ex) {
            Logger.getLogger(EmailSenderForm.class.getName()).log(Level.SEVERE, null, ex);
        }
    });
}

// Variables declaration - do not modify                     
private javax.swing.JTextField fieldAnexo;
private javax.swing.JTextField fieldSubject;
private javax.swing.JTextField fieldTo;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JLabel labelAnexo;
private javax.swing.JLabel labelAssunto;
private javax.swing.JLabel labelPara;
private javax.swing.JMenuItem menuItemExit;
private javax.swing.JMenuItem menuItemTools;
private javax.swing.JMenu menuPrincipal;
private javax.swing.JButton pesquisarBt;
private javax.swing.JButton sendEmail;
private javax.swing.JTextArea textAreaMessage;
// End of variables declaration