Q:

What is the simplest way to add an item to the beginning of a Java array

I need the simplest way to add an item to front of a Java array.
I need the Java array NOT the ArrayList.

A:

There are two ways to do this. One using an Objects or using generics. I recommend you to use generics because gives you more flexibility as you gonna see in the examples. He is a sniped using generics:
public static <T> T[] add2BeginningOfArray(T[] elements, T element)
{
    T[] newArray = Arrays.copyOf(elements, elements.length + 1);
    newArray[0] = element;
    System.arraycopy(elements, 0, newArray, 1, elements.length);

    return newArray;
}

To use it is really simple if you have a class Dot and you want to add an element to the beginning you just need to do this:
int size = 20;
Dot[] dots = new Dot[size];
for (int i = 0; i < size; i++) {
    dots[i] = new Dot("This is a dot");
}

Dot goal = new Dot("This is a goal");

System.out.println(Arrays.toString(add2BeginningOfArray(dots, goal)));

This implementation will help you to add any element to the beginning of an array of the same class as the element.
You can achieve the same using an Object as this example:
public static Object[] add2BeginningOfArray(Object[] elements, Object element){
    Object[] tempArr = new Object[elements.length + 1];
    tempArr[0] = element;
    System.arraycopy(elements, 0, tempArr, 1, elements.length);
}

Now what is the problem that you need to declare your array as Object[] and the use this kind of declaration to work with it.
Object[] foo = {"2", "3", "4"};
//adding an element to the beginning array
Object[] numbers = add2BeginningOfArray(foo, "1");
System.out.println(Arrays.toString(numbers));

A:

Apache Commons Lang class 'ArrayUtils' makes this very easy, if that is an option for you:
char[] arrayA = {'b', 'c'};
char[] arrayB = ArrayUtils.add(arrayA, 0, 'a');
// arrayB: [a, b, c]

A:

for(int i = roadVehicles.length; i > 0; i--) {
    if (roadVehicles[i-1] != null) {
        roadVehicles[i] = roadVehicles[i-1];                
    }
}
roadVehicles[0] = car;

