请问Android 怎么 重启一个activity

1.Intent intent = new Intent(this, Object.class); startActivity(intent); 2. 通过ActivityManager来重新启动应用程序： ActivityManager manager = （ActivityManager）this.getSystemService（Context.ACTIVITY_SERVICE）; manager.restartPackage("com.example.test"); 3. 通过flag来实现： private void restartApplication() {         final Intent intent = getPackageManager().getLaunchIntentForPackage(getPackageName());         intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);         startActivity(intent); } 4. 利用PendingIntent Intent mStartActivity = new Intent(context, StartActivity.class); int mPendingIntentId = 123456; PendingIntent mPendingIntent = PendingIntent.getActivity(context, mPendingIntentId,    mStartActivity, PendingIntent.FLAG_CANCEL_CURRENT); AlarmManager mgr = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE); mgr.set(AlarmManager.RTC, System.currentTimeMillis() + 100, mPendingIntent); System.exit(0);