I hope someone can explain this exercise to me. Thanks

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Programming Exercise

Try to think about how to implement KWArrayList class. Please implement the following constructor and methods:

public KWArrayList()

public boolean add(E anEntry)

public E get(int index) { 

public E set(int index, E newValue) 

public E remove(int index) 

private void reallocate() 

public int size() 

public int indexOf(Object item) 

Study the code for ArrayList implementation (enclosed in the folder) and work on the following exercise

Provide a constructor for class KWArrayList that accepts an int argument that represents the initial array capacity. Use this instead of INITIAL_CAPACITY.

2. Implement the indexOf method of the KWArrayList class.

3.Write statements to remove the middle object from a KWArrayList and place it at the end.

/**

Removes middle object and re-inserts it at the end

@return E object removed and re-inserted

*/

public E removeMiddleInsertEnd()

{

}

4. Please define a tester class to verify your code.

 import java.util.Arrays; import java.util.AbstractList; /** * This class implements some of the methods of the Java * ArrayList class. * @author Your Name */ public class KWArrayList extends AbstractList { // Data Fields /** The default initial capacity */ private static final int INITIAL_CAPACITY = 10; /** The underlying data array */ private E[] theData; /** The current size */ private int size = 0; /** The current capacity */ private int capacity = 0; /** * Construct an empty KWArrayList with the default * initial capacity */ public KWArrayList() { capacity = INITIAL_CAPACITY; theData = (E[]) new Object[capacity]; } /*Your programming exercise 1 goes here*/ /** * Construct an empty KWArrayList with a specified initial capacity * @param capacity The initial capacity */ /**/ /** * Appends the specified element to the end of this list. * * @param theEntry - The value to be inserted * @throws ArrayIndexOUtOfBoundsException if index is * less than zero or greater than size */ public boolean add(E anEntry) { if (size == capacity) { reallocate(); } theData[size] = anEntry; size++; return true; } /** * Get a value in the array based on its index. * @param index - The index of the item desired * @return The contents of the array at that index * @throws ArrayIndexOutOfBoundsException - if the index * is negative or if it is greater than or equal to the * current size */ public E get(int index) { if (index < 0 || index >= size) { throw new ArrayIndexOutOfBoundsException(index); } return theData[index]; } /** * Set the value in the array based on its index. * @param index - The index of the item desired * @param newValue - The new value to store at this position * @return The old value at this position * @throws ArrayIndexOutOfBoundsException - if the index * is negative or if it is greater than or equal to the * current size */ public E set(int index, E newValue) { if (index < 0 || index >= size) { throw new ArrayIndexOutOfBoundsException(index); } E oldValue = theData[index]; theData[index] = newValue; return oldValue; } /** * Remove an entry based on its index * @param index - The index of the entry to be removed * @return The value removed * @throws ArrayIndexOutOfBoundsException - if the index * is negative or if it is greater than or equal to the * current size */ public E remove(int index) { if (index < 0 || index >= size) { throw new ArrayIndexOutOfBoundsException(index); } E returnValue = theData[index]; for (int i = index + 1; i < size; i++) { theData[i - 1] = theData[i]; } size--; return returnValue; } /*Your programming exercise 3 goes here*/ /** Removes middle object and re-inserts it at the end @return E object removed and re-inserted */ public E removeMiddleInsertEnd() { } /** * Allocate a new array to hold the directory */ private void reallocate() { capacity = 2 * capacity; theData = Arrays.copyOf(theData, capacity); } /** * Get the current size of the array * @return The current size of the array */ public int size() { return size; } /*Your programming exercise 2 goes here*/ /** * Returns the index of the first occurence of the specified element * in this list, or -1 if this list does not contain the element * @param item The object to search for * @returns The index of the first occurence of the specified item * or -1 if this list does not contain the element */ public int indexOf(Object item) { } /**/ } /**/