如何使用java创建像Windows一样的屏幕键盘？

Question

我想通过单击按钮在记事本中写入数据。 通过使用我的代码我试图在记事本中写它不起作用。我想要像Windows的屏幕键盘一样的功能。通过Windows屏幕键盘，我们可以在记事本以及谷歌浏览器中编写，就像我想要创建应用程序一样。 如何使用java创建这样的？ 我尝试了以下方式，但它没有用。

import java.awt.AWTException;
import java.awt.Robot;
import java.awt.event.KeyEvent;
import java.util.logging.Level;
import java.util.logging.Logger;


public class OnclickTest extends javax.swing.JFrame {


Robot robot;
public OnclickTest() throws AWTException {
    initComponents();
    robot = new Robot();
}


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

    jButton1 = new javax.swing.JButton();
    jButton2 = new javax.swing.JButton();
    jButton3 = new javax.swing.JButton();
    jButton4 = new javax.swing.JButton();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jButton1.setText("PAGE UP");
    jButton1.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton1ActionPerformed(evt);
        }
    });

    jButton2.setText("PAGE DOWN");
    jButton2.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton2ActionPerformed(evt);
        }
    });

    jButton3.setText("A");
    jButton3.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton3ActionPerformed(evt);
        }
    });

    jButton4.setText("B");
    jButton4.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton4ActionPerformed(evt);
        }
    });

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGap(60, 60, 60)
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                .addComponent(jButton3)
                .addComponent(jButton1))
            .addGap(31, 31, 31)
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addComponent(jButton2)
                .addComponent(jButton4))
            .addContainerGap(141, Short.MAX_VALUE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGap(68, 68, 68)
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jButton1)
                .addComponent(jButton2))
            .addGap(18, 18, 18)
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jButton3)
                .addComponent(jButton4))
            .addContainerGap(168, Short.MAX_VALUE))
    );

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

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
    robot.keyPress(KeyEvent.VK_PAGE_UP);
    robot.keyRelease(KeyEvent.VK_PAGE_UP);
}                                        

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
    robot.keyPress(KeyEvent.VK_PAGE_DOWN);
    robot.keyRelease(KeyEvent.VK_PAGE_DOWN);
}                                        

private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
    robot.keyPress(KeyEvent.VK_A);
    robot.keyRelease(KeyEvent.VK_A);
}                                        

private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
    robot.keyPress(KeyEvent.VK_B);
    robot.keyRelease(KeyEvent.VK_B);
}                                        

/**
 * @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(OnclickTest.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(OnclickTest.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(OnclickTest.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(OnclickTest.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() {
            try {
                new OnclickTest().setVisible(true);
            } catch (AWTException ex) {
                Logger.getLogger(OnclickTest.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    });
}

// Variables declaration - do not modify                     
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JButton jButton4;

}