This is a robot or ProbeRobot problem.

If use probot.pressShift() to press the shift key down and later
on the shift key can not be released until user hit shift key by hand.
probot.releaseShift() does not work.


We found this is a bug in probeRobot, method keyRelease() in probeRobot
call robot keyPress() instead of keyRelease(), this is the reason that
the shift key can not be released, below is the method in probot.
public void keyRelease(int i, int j)
    {
        robot.keyPress(j);// It should have been robot.keyRelease(j)
instead
        pause(i);
    }


Below is the new test file use robot for this bug, it passes:
import java.awt.*;
import java.awt.event.*;

public class ShiftTest extends Frame implements ActionListener {
TextField tf;
Robot rbt;

public ShiftTest() {
    setLayout(new FlowLayout());
    rbt = new Robot();
    tf = new TextField(30);
    tf.addActionListener(this);
    add(new Label("Testing Shift Key Press"));
    add(tf);
    pack();
    setVisible(true);
}

public void actionPerformed(ActionEvent e) {
    System.out.println("inside actionevent");
}
public static void main(String[] args) {
    ShiftTest test = new ShiftTest();
    //test.rbt.setAutoDelay(1000);
    //test.rbt.mouseMove(test.tf.getX()+2,test.tf.getY()+2);
    test.rbt.setAutoDelay(1000);
    test.rbt.keyPress(KeyEvent.VK_A);
    test.rbt.setAutoDelay(1000);
    test.rbt.keyPress(KeyEvent.VK_SHIFT);
    test.rbt.setAutoDelay(1000);
    test.rbt.keyPress(KeyEvent.VK_A);
    test.rbt.setAutoDelay(1000);
    test.rbt.keyRelease(KeyEvent.VK_SHIFT);
    test.rbt.setAutoDelay(1000);
    test.rbt.keyPress(KeyEvent.VK_A);
    test.rbt.setAutoDelay(1000);
    test.dispose();
    System.exit(0);
}
}