INTRO JAVA

This is my version of the class ArrayList, called ListArray. Please change it to a GENERIC CLASS. You will need to store an array of Objects and cast to the generic type E when needed (such as when returning an element stored in the ArrayList). Here is my ArrayList (not generic): Please make all changes needed to make it compltely generic.

public class ListArray {

private String[] array;

private int numElements;

public ListArray() {

array = new String[10];

numElements = 0;

}

public ListArray(int size) {

array = new String[size];

numElements = 0;

}

/**

* Copy constructor for ListArray

* Creates a new list array of the

* same size as the ListArray passed

* in as a parameter, and copies the

* parameter's data into the new

* list array using a for loop

* Also sets the numElements to be

* the same as the parameter's

* numElements

* @param la the ListArray to copy

*/

public ListArray(ListArray la) {

array = new String[la.array.length];

for (int i = 0; i < la.size(); i++) {

array[i] = la.get(i);

}

numElements = la.size();

}

/**Accessor Methods*/

/**

* Returns whether the list array is

* currently empty

* @return whether the list array is

* empty

*/

public boolean isEmpty() {

for (int i = 0; i < array.length; i++) {

if (array[i] != null) {

return false;

}

}

return true;

}

/**

* Returns the current number of

* elements stored in the list

* array

* @return the number of elements

*/

public int size() {

/*

for (int i = 0; i < array.length - 1; i++) {

while (!array[i].equals("null")) {

numElements++;

}

}

*/

return numElements;

}

/**

* Returns the element at the specified

* index. Prints an error message and

* returns an empty String if index is

* larger than or equal to numElements

* @param index the index of the element

* to access

* @return the element at index

*/

public String get(int index) {

if (index >= numElements) {

System.out.println("Error: Cannot get element at index " + index + "." +

" Outside bounds of list array.");

System.out.println("Index: " + index + ", Size: " + numElements);

return null;

} else {

return array[index];

}

}

/**

* Uses the linearSearch algorithm to

* locate an element in the list array

* @param str the element to locate

* @return whether or not the element

* is in the list array

*/

public boolean contains(String str) {

for (int i = 0; i < numElements; i++) {

if (array[i].equals(str)) {

return true;

}

}

return false;

}

/**

* Uses the linearSearch algorithm to

* locate an element in the list array

* @param str the element to locate

* @return the location of the element

* or -1 if the element is not in the

* list array

*/

public int indexOf(String str) {

for (int i = 0; i < numElements; i++) {

if (array[i].equals(str)) {

return i;

}

}

return -1;

}

/**

* Determines whether the list array

* is currently full

* @return whether the list array

* is at maximum capacity

*/

private boolean atCapacity() {

boolean isFull = true;

for(int i = 0; i < array.length; i++) {

if(array[i] == null) {

isFull = false;

break;

}

}

return isFull;

}

/**Mutator Methods*/

/**

* Resizes the list array by making a new

* array that has a length (capacity)

* 10 larger than the current array's

* length (capacity)

*/

private void reSize() {//array2 never gets passed back to the main code

int newlength = array.length + 10;

String array2[] = new String[newlength];

for (int i = 0; i < array.length; i++) {

array2[i] = array[i];

}

array = array2;

}

/**

* Inserts a new element to the end

* of the list array.

* Resizes the list array if it is

* at capacity before inserting

* @param str the element to insert

*/

public void add(String str) {

if (atCapacity()) {

reSize();

}

array[numElements] = str;

numElements++;

}

/**

* Inserts a new element at the specified

* index in the list array.

* Resizes the list array if it is

* at capacity before inserting

* @param index the index at which to insert

* @param str the element to insert

*/

public void add(int index, String str) {

if (index > array.length - 1) {

System.out.println("Error: Cannot add element " + str + " at index " + index + ".");

System.out.println("Index is outside the bounds of the list array.");

System.out.println("Index: " + index + ", Size: " + size());

return;

}

if (atCapacity()) {

reSize();

array[index] = str;

}

for(int i = numElements; i > index; i--) {

array[i] = array[i - 1];

}

array[index] = str;

numElements++;

}

/**

* Assigns a new value to the list array

* at a specified index

* @param index the index at which to update

* @param str the new element

*/

public void set(int index, String str) {

array[index] = str;

}

/**

* Removes an element at a specified index in

* the list array

* @param index the index at which to remove

* @return the element that was removed

*/

public String remove(int index) {

if (index >= array.length) {

System.out.println("Error: Cannot remove element at index " + index + ". Outside bounds of list array.");

return "";

}

String removed = array[index];

for (int i = index; i < array.length - 1; i++) {

array[i] = array[i + 1];

}

numElements--;

return removed;

}

/**

* Removes the first instance of the specified

* element in the list array

* @param str the element to remove

* @return whether the element was successfully

* removed

*/

public boolean remove(String str) {

boolean result = false;

int index = -1;

for (int i = 0; i < numElements; i++) {

if (array[i].equals(str)) {

index = i;

break;

}

}

if (index == -1) {

System.out.println("Error: Cannot remove element " + str + ". No such element in the list array.");

return result;

}

for (int i = index; i < array.length - 1; i++) {

array[i] = array[i + 1];

}

result = true;

numElements--;

return result;

}

/**Additional Methods*/

/**

* Creates a String of all elements,

* with [] around the elements,

* each element separated from the next

* with a comma

*/

@Override public String toString() {

String formattedArr = "";

for(int i = 0; i < numElements; i++) {

formattedArr = formattedArr + array[i];

if (i + 1 < numElements) {

formattedArr = formattedArr + ", ";

}

}

return "[" + formattedArr + "]";

}

}