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POGUID to ByteArray
 

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    <p>I just wrote this code to convert a GUID into a byte array. Can anyone shoot any holes in it or suggest something better?</p> <pre><code> public static byte[] getGuidAsByteArray(){ UUID uuid = UUID.randomUUID(); long longOne = uuid.getMostSignificantBits(); long longTwo = uuid.getLeastSignificantBits(); return new byte[] { (byte)(longOne &gt;&gt;&gt; 56), (byte)(longOne &gt;&gt;&gt; 48), (byte)(longOne &gt;&gt;&gt; 40), (byte)(longOne &gt;&gt;&gt; 32), (byte)(longOne &gt;&gt;&gt; 24), (byte)(longOne &gt;&gt;&gt; 16), (byte)(longOne &gt;&gt;&gt; 8), (byte) longOne, (byte)(longTwo &gt;&gt;&gt; 56), (byte)(longTwo &gt;&gt;&gt; 48), (byte)(longTwo &gt;&gt;&gt; 40), (byte)(longTwo &gt;&gt;&gt; 32), (byte)(longTwo &gt;&gt;&gt; 24), (byte)(longTwo &gt;&gt;&gt; 16), (byte)(longTwo &gt;&gt;&gt; 8), (byte) longTwo }; } </code></pre> <p>In C++, I remember being able to do this, but I guess theres no way to do it in Java with the memory management and all?:</p> <pre><code> UUID uuid = UUID.randomUUID(); long[] longArray = new long[2]; longArray[0] = uuid.getMostSignificantBits(); longArray[1] = uuid.getLeastSignificantBits(); byte[] byteArray = (byte[])longArray; return byteArray; </code></pre> <h2>Edit</h2> <p>If you want to generate a completely random UUID as bytes that does not conform to any of the official types, this will work and wastes <a href="http://en.wikipedia.org/wiki/Universally_Unique_Identifier">10 fewer bits</a> than type 4 UUIDs generated by UUID.randomUUID():</p> <pre><code> public static byte[] getUuidAsBytes(){ int size = 16; byte[] bytes = new byte[size]; new Random().nextBytes(bytes); return bytes; } </code></pre>
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    1. CODupe - http://stackoverflow.com/questions/1055413 ?
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    2. CONo, I was mentioning that in C++, you could have skipped having to copy everything into another array, but it doesn't look like you can do that in Java.
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    3. COpossible duplicate of [Sending a Java UUID to C++ as bytes and back over TCP](http://stackoverflow.com/questions/1055413/sending-a-java-uuid-to-c-as-bytes-and-back-over-tcp)
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