Using Java UUID in Matlab

I am trying to use JAVA UUIDs to identify the objects in my code. When I try to print it inside an fprintf, I get a weird error. I could print it in disp but that is not ideal since I want a good formatted message.

>> temp =  java.util.UUID.randomUUID;
>> myuuid = temp.toString;
>> disp(myuuid)
a8a4eae2-6cc7-47d3-b58e-408b71fab260

>> fprintf(myuuid)
Error using fprintf
Invalid file identifier.  Use fopen to generate a valid file identifier.

Any help in understanding or fixing this error is appreciated.

[David Galbally]

>> temp = java.util.UUID.randomUUID;

>> myuuid = temp.toString;

>> MATLABstr = myuuid.toCharArray';

>> fprintf(MATLABstr)

Answer 1

[Walter Roberson]

Try

fprintf('%s\n' myuuid);

If that doesn't work then

fprintf('%s\n', char(myuuid));

[Gurudatha Pai]

that also doesn't work

>> fprintf('%s',myuuid)
Error using fprintf
Function is not defined for 'java.lang.String' inputs.

[Walter Roberson]

It appears that I was adding a second option to my answer just as you replied. Did you get a chance to try

fprintf('%s\n', char(myuuid));

[Emile Glorieux]

This doesn't work for me.

>> fprintf('%s\n', char(myuuid));
Undefined function or variable 'myuuid'.

Answer 2

[Philipp Tempel]

This may be too stupid to be true but, looking at the source code of tempname(), you can see that you can simply do

uuid = char(matlab.lang.internal.uuid())

[Andrei Veldman]

True, but then you would be using an undocumented Matlab feature, which could change without warning...

Answer 3

[Andrei Veldman]

...or, using pure Matlab (no need for converting form Java):

[~,guid] = fileparts(tempname)

guid = 'tp8d1a6bd2_0ac7_4c0a_8d3d_b32e4e97b746'