我是Java的新手，我需要更改进度条的背景颜色，但我真的不知道怎么做 我有一个名为“barrita”的进度条 我正在使用Linux Ubuntu和Java 8，我正在使用Swing的调色板
package loginprogressbar;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.JOptionPane;
import javax.swing.Timer;
/**
*
* @author fernando
*/
public class Inicio extends javax.swing.JFrame {
private Timer tiempo;
int contador;
public static final int TWO_SECOND = 2;
class TimerListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
contador += 1;
barrita.setValue(contador);
if (contador == 100) {
tiempo.stop();
esconder();
Menu1 m1 = new Menu1();
m1.setVisible(true);
m1.setLocationRelativeTo(null);
}
}
}
public void esconder() {
this.setVisible(false);
}
public void activar() {
tiempo.start();
}
public Inicio() {
initComponents();
setLocationRelativeTo(null);
barrita.setVisible(false);
}
public void inicionSesion() {
String usuario = panel2.getText();
String password = (String.valueOf(txtPassword.getText()));
if (usuario.equals("fernando") && password.compareTo("12345") == 0) {
barrita.setVisible(true);
contador = -1;
barrita.setValue(0);
barrita.setStringPainted(true);
tiempo = new Timer(TWO_SECOND, new TimerListener());
activar();
} else {
JOptionPane.showMessageDialog(null, "Error al ingresar usuario o contraseña incorrecta");
panel2.setText("");
txtPassword.setText("");
panel2.requestFocus();
}
}
/**
* 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() {
panel1 = new javax.swing.JPanel();
panel2 = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
txtPassword = new javax.swing.JPasswordField();
btnEntrar = new javax.swing.JButton();
barrita = new javax.swing.JProgressBar();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
getContentPane().setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());
panel1.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
panel1KeyPressed(evt);
}
});
panel2.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
panel2KeyPressed(evt);
}
});
jLabel1.setText("Nombre");
jLabel2.setText("Contraseña");
txtPassword.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
txtPasswordKeyPressed(evt);
}
});
btnEntrar.setText("Ingresar");
btnEntrar.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btnEntrarActionPerformed(evt);
}
});
javax.swing.GroupLayout panel1Layout = new javax.swing.GroupLayout(panel1);
panel1.setLayout(panel1Layout);
panel1Layout.setHorizontalGroup(
panel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, panel1Layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(btnEntrar)
.addGap(83, 83, 83))
.addGroup(panel1Layout.createSequentialGroup()
.addGap(58, 58, 58)
.addGroup(panel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(panel1Layout.createSequentialGroup()
.addComponent(barrita, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(panel1Layout.createSequentialGroup()
.addGroup(panel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addComponent(jLabel2))
.addGap(18, 18, 18)
.addGroup(panel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(txtPassword)
.addComponent(panel2, javax.swing.GroupLayout.DEFAULT_SIZE, 130, Short.MAX_VALUE))
.addGap(113, 113, 113))))
);
panel1Layout.setVerticalGroup(
panel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(panel1Layout.createSequentialGroup()
.addGap(39, 39, 39)
.addGroup(panel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(panel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel1))
.addGap(21, 21, 21)
.addGroup(panel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(txtPassword, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(26, 26, 26)
.addComponent(barrita, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(btnEntrar)
.addContainerGap(93, Short.MAX_VALUE))
);
getContentPane().add(panel1, new org.netbeans.lib.awtextra.AbsoluteConstraints(0, 0, 400, 300));
pack();
}// </editor-fold>
private void panel1KeyPressed(java.awt.event.KeyEvent evt) {
if (evt.getKeyCode() == KeyEvent.VK_ENTER) {
inicionSesion();
}
}
private void btnEntrarActionPerformed(java.awt.event.ActionEvent evt) {
inicionSesion(); // TODO add your handling code here:
}
private void txtPasswordKeyPressed(java.awt.event.KeyEvent evt) {
if (evt.getKeyCode() == KeyEvent.VK_ENTER) {
btnEntrar.requestFocus();
}
}
private void panel2KeyPressed(java.awt.event.KeyEvent evt) {
if (evt.getKeyCode() == KeyEvent.VK_ENTER) {
txtPassword.requestFocus();
}
}
/**
* @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(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Inicio().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JProgressBar barrita;
private javax.swing.JButton btnEntrar;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JPanel panel1;
private javax.swing.JTextField panel2;
private javax.swing.JPasswordField txtPassword;
// End of variables declaration
}