Best way to close and shutdown objects in onDestroy

Inside the onDestroy method, whats the correct way to determine if an object was actually initialized before trying to close it/shut it down/etc.

For example, which is better:

protected void onDestroy()
{
    if(tts != null)
    {
        tts.shutdown();
    }

    if(dbWord != null)
    {
        dbWord.close(开发者_StackOverflow中文版);
    }

    super.onDestroy();
}

or this:

protected void onDestroy()
{
    if(tts instanceof  null)
    {
        tts.shutdown();
    }

    if(dbWord instanceof TextToSpeech)
    {
        dbWord.close();
    }

    super.onDestroy();
}

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Use != instead of instanceOf to check if a variable was initialized. instanceOf performs additional type checking which you do not need in this case.

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Use !=, don't use instanceOf. When you declare an object, it's already an instance of some class, even it's not initialized, NULL certainly.
The first one of yours is correct way to handle.