Regarding autodie :

Those frameworks normally use quite antique Perl versions and installing modules shouldn't be easy.

But the documentation for open already has it all:

 open(my $fh, "<", "input.txt") 
    or die "cannot open < input.txt: $!";
[download]

and so on for print and close

you said your JAVA-process hangs...

...IF the Perl process was really erminated I can't see a sane reason for this, except that the JAVA process is faulty.

Consider file system problems or race conditions...

Otherwise call IBM support.