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

public class LightMIDlet extends MIDlet {
  static LightMIDlet instance;
  LightForm displayable = new LightForm(this);
  public LightMIDlet() {
    instance = this;
  }

  public void startApp() {
    Display.getDisplay(this).setCurrent(displayable);
  }

  public void pauseApp() {
  }

  public void destroyApp(boolean unconditional) {
  }

  public static void quitApp() {
    instance.destroyApp(true);
    instance.notifyDestroyed();
    instance = null;
  }

}



//文件名：LightForm.java

package light;

import javax.microedition.lcdui.*;

public class LightForm extends Form implements CommandListener {
  StringItem si;
  Command cmdOpen;
  Command cmdClose;
  Command cmdExit;
  Display display;
  public LightForm(LightMIDlet lm) {
    super("手電筒");
    si = new StringItem("手電筒狀態(tài)：","打開(kāi)");
    this.append(si);

    display = Display.getDisplay(lm);

    cmdOpen = new Command("打開(kāi)",Command.OK,1);
    this.addCommand(cmdOpen);

    cmdClose = new Command("關(guān)閉",Command.CANCEL,1);
    this.addCommand(cmdClose);

    cmdExit = new Command("退出",Command.EXIT,1);
    this.addCommand(cmdExit);

    setCommandListener(this);

    boolean b;

    b = display.flashBacklight(1000000);

    if(b == false){
      Alert alert = new Alert("手電筒","您的手機(jī)不支持該功能!",null,AlertType.INFO);
      alert.setTimeout(3000);
      display.setCurrent(alert);
    }
  }

  public void commandAction(Command c, Displayable d) {
    //關(guān)閉
    if (c == cmdExit) {
      // stop the MIDlet
      LightMIDlet.quitApp();
    }
    //打開(kāi)
    if(c == cmdOpen){
      display.flashBacklight(1000000);
      si.setText("打開(kāi)");
    }

    if(c == cmdClose){
      display.flashBacklight(0);
      si.setText("關(guān)閉");
    }
  }

}