播放不同的Alert声音

import Javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class SoundAlert extends MIDlet implements ItemStateListener, CommandListener
{
  private Display display;      // Reference to display object
  private Form fmMain;         // Main form
  private Command cmExit;      // Command to exit the MIDlet
  private ChoiceGroup cgSound; // Choice group

  public SoundAlert()
  {
    display = Display.getDisplay(this);

    // Create an exclusive (radio) choice group
    cgSound = new ChoiceGroup("Choose a sound", Choice.EXCLUSIVE);
    // Append options, with no associated images
    cgSound.append("Info", null);
    cgSound.append("Confirmation", null);
    cgSound.append("Warning", null);
    cgSound.append("Alarm", null);
    cgSound.append("Error", null);

    cmExit = new Command("Exit", Command.EXIT, 1);

    // Create Form, add components, listen for events
    fmMain = new Form("");
    fmMain.append(cgSound);
    fmMain.addCommand(cmExit);
    fmMain.setCommandListener(this);
    fmMain.setItemStateListener(this);
  }

  public void startApp()
  {
    display.setCurrent(fmMain);
  }

  public void pauseApp()
  { }
  public void destroyApp(boolean unconditional)
  { }

  public void commandAction(Command c, Displayable s)
  {
    if (c == cmExit)
    {
      destroyApp(false);
      notifyDestroyed();
    }
  }
  public void itemStateChanged(Item item)
  {
    switch (cgSound.getSelectedIndex())
    {
      case 0:
        AlertType.INFO.playSound(display);
        break;

      case 1:
        AlertType.CONFIRMATION.playSound(display);
        break;

      case 2:
        AlertType.WARNING.playSound(display);
        break;

      case 3:
        AlertType.ALARM.playSound(display);
        break;

      case 4:
        AlertType.ERROR.playSound(display);
        break;
    }
  }
}

（出处：）