java教学案例

package enter; import java.awt.Font; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPasswordField; import javax.swing.JTextField; public class Enter { private JPasswordField passwordField; private JTextField textField; private JFrame frame; /** * Launch the application * * @param args */ public static void main(String args[]) { try { Enter window = new Enter(); window.frame.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } /** * Create the application */ public Enter() { initialize(); } /** * Initialize the contents of the frame */ private void initialize() { frame = new JFrame(); frame.setTitle("键盘确认测试程序"); frame.getContentPane().setLayout(null); frame.setBounds(100, 100, 323, 245); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); final JLabel usernameLabel = new JLabel(); usernameLabel.setText("用户名："); usernameLabel.setBounds(59, 83, 60, 15); frame.getContentPane().add(usernameLabel); final JLabel passwordLabel = new JLabel(); passwordLabel.setText("密 码："); passwordLabel.setBounds(59, 117, 60, 15); frame.getContentPane().add(passwordLabel); final JLabel enterTestLabel = new JLabel(); enterTestLabel.setFont(new Font("", Font.PLAIN, 22)); enterTestLabel.setText("键盘按键确认测试程序"); enterTestLabel.setBounds(40, 21, 231, 33); frame.getContentPane().add(enterTestLabel); textField = new JTextField(); textField.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) { if (e.getKeyCode() == KeyEvent.VK_ENTER) { // 跳到下一个文本输入框内等待输入 view(); } } }); textField.setBounds(139, 80, 112, 21); frame.getContentPane().add(textField); passwordField = new JPasswordField(); passwordField.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) { if (e.getKeyCode() == KeyEvent.VK_ENTER) { view(); } } }); passwordField.setBounds(139, 112, 112, 25); frame.getContentPane().add(passwordField); final JButton okButton = new JButton(); okButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { view(); } }); okButton.setText("提交"); okButton.setBounds(59, 164, 83, 25); frame.getContentPane().add(okButton); final JButton aboutButton = new JButton(); aboutButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { About abo = new About(); abo.show(); } }); aboutButton.setText("关于"); aboutButton.setBounds(168, 164, 83, 25); frame.getContentPane().add(aboutButton); } public void view() { String user=textField.getText(); char[] pass1=passwordField.getPassword(); String pass=String.copyValueOf(pass1); // System.out.println(pass); if (!user.equals("")&& !pass.equals("")) { JOptionPane.showMessageDialog(null, "输入正确！", "提示", JOptionPane.INFORMATION_MESSAGE); // System.exit(0); } else { System.out.print(passwordField.getPassword()); JOptionPane.showMessageDialog(null, "错了没有呀？文本框都要有内容的哦！", "提示", JOptionPane.INFORMATION_MESSAGE); } } }