1. Overview
In this short tutorial, we'll see how to convert between a byte array and UUID in Java.
2. Convert UUID to Byte Array
We can easily convert a UUID to a byte array in plain Java:
public static byte[] convertUUIDToBytes(UUID uuid) {
ByteBuffer bb = ByteBuffer.wrap(new byte[16]);
bb.putLong(uuid.getMostSignificantBits());
bb.putLong(uuid.getLeastSignificantBits());
return bb.array();
}
3. Convert Byte Array to UUID
Converting a byte array to UUID is just as simple:
public static UUID convertBytesToUUID(byte[] bytes) {
ByteBuffer byteBuffer = ByteBuffer.wrap(bytes);
long high = byteBuffer.getLong();
long low = byteBuffer.getLong();
return new UUID(high, low);
}
4. Test Our Methods
Let's test our methods:
UUID uuid = UUID.randomUUID();
System.out.println("Original UUID: " + uuid);
byte[] bytes = convertUUIDToBytes(uuid);
System.out.println("Converted byte array: " + Arrays.toString(bytes));
UUID uuidNew = convertBytesToUUID(bytes);
System.out.println("Converted UUID: " + uuidNew);
The result will look something like:
Original UUID: bd9c7f32-8010-4cfe-97c0-82371e3276fa
Converted byte array: [-67, -100, 127, 50, -128, 16, 76, -2, -105, -64, -126, 55, 30, 50, 118, -6]
Converted UUID: bd9c7f32-8010-4cfe-97c0-82371e3276fa
5. Conclusion
In this quick tutorial, we've learned how to convert between a byte array and UUID in Java.
As always, the example code from this article can be found over on GitHub.
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