MersenneTwister random number generator

I have a list(with 100.000 data) and i want to choose 4000 of them using MersenneTwister. I also want to use current system time because i run 15 times the program and i need different number of times.

MersenneTwister mt = new MersenneTwister("current system function");
for(int i=0; i<4000; i++){
    list1.add(mt.nextDouble());
}

I think that i must write something like this but i dont know which current system function to use to take different numbers