How to generate a unique Long value in Java? : <p>everyone.</p>

<p>I have a simple question. Is the value returned by <code>UUID.randomUUID().getMostSignificantBits()</code> ALWAYS unique?</p>

<p>I need to generate a Long value which needs to ALWAYS be unique. Is there any other way to generate a Long that accomplishes this?</p>

<p>Thanks.</p>
