code: public static double exponentialCdf(double x, double lamda) {
          if(x<0 || lamda<=0) {
              throw new IllegalArgumentException("All the parameters must be positive.");
          }
          
          double probability = 1.0 - Math.exp(-lamda*x);
          
          return probability;
      }
docs: Calculates the probability from 0 to X under Exponential Distribution
  
  @param x
  @param lamda
  @return