Experiment controller using a generic array and method

I am trying to find the time it takes for a Bubble sort method of sorting an integer array vs a selection sort.

public class ExperimentController
{
private static int[] intArray = {};
public static void main(String[] args)
{
System.out.println("");
ExperimentController EX = new ExperimentController();
for(int i =0; i<=300;i=i+50){
long time = EX.timeBubbleSortPerformance(i, 0);
System.out.println(time);
}
}
public long timeBubbleSortPerformance(int numberOfItems, int seed){
long startTime = System.nanoTime();
RandomStuffContainer RSC = new RandomStuffContainer();
Random random = new Random(seed);
for(int i=0; i<numberOfItems; i++){
int randomInt = random.nextInt();
RSC.addToFront(intArray[randomInt]);   
RSC.selectionSort(intArray[randomInt]);   
}
long stopTime = System.nanoTime();
long timeTotal = stopTime-startTime;
return timeTotal;
}
}

The method calls the Random stuff container class for the methods.

public class RandomStuffContainer<T extends Comparable<T>>
{
ArrayList<T> array = new ArrayList<T>();
public  void main(String[] args){
ArrayList<T> array = new ArrayList<T>();
}
public void addToFront(T value)
{
array.add(0, value);
}
/**
* Adds the inputted String i to the back of the Arraylist
*
* @param  A generic parameter T
*/
public void addToBack(T value)
{
array.add(value);
}
/**
* Sorts the Arraylist using selection sort algorithim
*
*/
public void selectionSort() 
{
for(int i=0; i<array.size() -1; i++)
{
int smallestIndex = i;
for(int j=i+1; j<array.size(); j++)
{
if(array.get(smallestIndex).compareTo((array.get(j))) > 0  )
{
smallestIndex = j;
}
}
T temp = array.get(i);
array.add(i,array.get(smallestIndex));
array.add(smallestIndex, temp);
} 
}
public void bubbleSort(){
T temp;
if (array.size()>1) // check if the number of orders is larger than 1
{
for (int x=0; x<array.size(); x++) // bubble sort outer loop
{
for (int i=0; i < array.size()-i; i++) {
if (array.get(i).compareTo(array.get(i+1)) > 0)
{
temp = array.get(i);
array.set(i,array.get(i+1) );
array.set(i+1, temp);
}
}
}
}
}
/**
* Copies array list data to String and returns String.
* Used for testing
*/
public String toString() {
{
StringBuilder sb = new StringBuilder();
for (T s : array)
{
sb.append(s.toString());
sb.append("\t");
}      
return  sb.toString();
}
}
}

I am trying to use random to randomly fill the array in RandomStuffContainer with ints and then use the sort method to sort that and get the runtime from it. I know my code is messy and sorry for that but any help would be very much appreciated.

Enable all compiler warnings, and pay attention to them. The compiler will tell you that you forgot to specify a type in RandomStuffContainer RSC = new RandomStuffContainer();. You probably wanted to do this:

RandomStuffContainer<Integer> RSC = new RandomStuffContainer<>();

Also, random.nextInt() returns a random 32-bit int value. The returned value is by no means guaranteed to be a valid index in intArray.

You’ll want to limit the value returned:

int randomInt = random.nextInt(intArray.length);

Look at the selectionSort method in RandomStuffContainer. It does not take any arguments. So you should not be passing any arguments to it. Again, the compiler told you this.

You should not call selectionSort every time you add something to the RandomStuffContainer. Give the container all the elements, and after the loop is done, call selectionSort().