将UUID转换为GUID，反之亦然

Question

I have this UUID which is changed inside a hqlQuery result when querying a MSSQL database:

createQuery("... where UUID = '917f116e-3447-4524-a959-ece721413f93'").list() //finds the right object

but returns an object with a modified UUID 6e117f91-4734-2445-a959-ece721413f93

917f116e-3447-4524-a959-ece721413f93 // correct UUID goes into query
6e117f91-4734-2445-a959-ece721413f93 // modified UUID from the resultset

now when i do a query with the modified UUID:

createQuery("... where UUID = '6e117f91-4734-2445-a959-ece721413f93'").list() 

i don't find an object.

So i need to convert the modified one back to the original (and also the other way around). I don't know if this is an little vs big endian issue.

Answer 1

I make no claim this is the best solution, but this is a solution. This should encode big endian into little endian and vice versa.

import java.util.UUID;

// ...

 public static UUID uuidMarshalIntoMSFormat(UUID uuid)
  {
    if (uuid == null)
    {
      throw new IllegalArgumentException("Parameter, uuid cannot be null");
    }

    final long msbBigEndian = uuid.getMostSignificantBits();
    final long msbLittleEndian =
      ((msbBigEndian & 0x0000_00FF_0000_0000L) << 24) |
        ((msbBigEndian & 0x0000_FF00_0000_0000L) << 8) |
        ((msbBigEndian & 0x00FF_0000_0000_0000L) >>> 8) |
        ((msbBigEndian & 0xFF00_0000_0000_0000L) >>> 24) |
        ((msbBigEndian & 0x0000_0000_FF00_0000L) >>> 8) |
        ((msbBigEndian & 0x0000_0000_00FF_0000L) << 8) |
        ((msbBigEndian & 0x0000_0000_0000_FF00L) >>> 8) |
        ((msbBigEndian & 0x0000_0000_0000_00FFL) << 8);
    return new UUID(msbLittleEndian, uuid.getLeastSignificantBits());
  }