listing 6-2.java

来自「这是JAVA开发大全的源代码」· Java 代码 · 共 61 行

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class DisplayAlert extends MIDlet implements CommandListener
{
  private Display display; 
  private Alert alert;
  private Form form; 
  private Command exit; 
  private boolean exitFlag; 
  public DisplayAlert()
  {
    exitFlag = false;
    display = Display.getDisplay(this);
    exit = new Command("Exit", Command.SCREEN, 1);
    form = new Form("Throw Exception");
    form.addCommand(exit);
    form.setCommandListener(this);
  }
  public void startApp()
  {
   display.setCurrent(form);
  }
  public void pauseApp()
  {
  }
  public void destroyApp(boolean unconditional) 
        throws MIDletStateChangeException
  {
    if (unconditional == false)
    {
     throw new MIDletStateChangeException();
    }
  }      
  public void commandAction(Command command, Displayable displayable)
  {
    if (command == exit)
    {
      try
      {
        if (exitFlag == false)
        {
         alert = new Alert("Busy", "Please try again.", 
                           null, AlertType.WARNING); 
         alert.setTimeout(Alert.FOREVER); 
         display.setCurrent(alert, form);
         destroyApp(false);
        }
        else
        {
         destroyApp(true);
         notifyDestroyed();
        }
      }
      catch (MIDletStateChangeException exception)
      {
        exitFlag = true; 
      }
    }
  }
}