JAVA - exponential distribution

Question

I need to find a formula for exponential distribution of probability, but I don´t know how to find it. This formula has to have powerful statistical properties (it can´t throw away any result from random to keep indistructed seek of random instance).

I am trying to find formula, which will work in a method like this:

rand.getNextDoubleExpDistrib();

I have this code for now, but according to "input analyser", it doesn´t work correctly

public double getNext() {
    return -lampda * Math.log(rand.nextDouble());
}

Answer 1

You can see this answer : Pseudorandom Number Generator - Exponential Distribution

Here the java code

public double getNext() {
    return  Math.log(1-rand.nextDouble())/(-lambda);
}

Have a nice day