Implement the methods union and intersection for the ArrayBag class. ArrayBag class is given to you below. You must place these methods in that class and test them in the main.

/**

A class of bags whose entries are stored in a fixed-size array.

@author Frank M. Carrano

@author Timothy M. Henry

@version 4.0

*/

public final class ArrayBag implements BagInterface

{

private final T[] bag;

private int numberOfEntries;

private boolean initialized = false;

private static final int DEFAULT_CAPACITY = 25;

private static final int MAX_CAPACITY = 10000;

/** Creates an empty bag whose initial capacity is 25. */

public ArrayBag()

{

this(DEFAULT_CAPACITY);

} // end default constructor

/** Creates an empty bag having a given capacity.

@param desiredCapacity The integer capacity desired. */

public ArrayBag(int desiredCapacity)

{

if (desiredCapacity <= MAX_CAPACITY)

{

// The cast is safe because the new array contains null entries

@SuppressWarnings("unchecked")

T[] tempBag = (T[])new Object[desiredCapacity]; // Unchecked cast

bag = tempBag;

numberOfEntries = 0;

initialized = true;

}

else

throw new IllegalStateException("Attempt to create a bag " +

"whose capacity exceeds " +

"allowed maximum.");

} // end constructor

/** Adds a new entry to this bag.

@param newEntry The object to be added as a new entry.

@return True if the addition is successful, or false if not. */

public boolean add(T newEntry)

{

checkInitialization();

boolean result = true;

if (isArrayFull())

{

result = false;

}

else

{ // Assertion: result is true here

bag[numberOfEntries] = newEntry;

numberOfEntries++;

} // end if

return result;

} // end add

/** Retrieves all entries that are in this bag.

@return A newly allocated array of all the entries in this bag. */

public T[] toArray()

{

checkInitialization();

// The cast is safe because the new array contains null entries.

@SuppressWarnings("unchecked")

T[] result = (T[])new Object[numberOfEntries]; // Unchecked cast

for (int index = 0; index < numberOfEntries; index++)

{

result[index] = bag[index];

} // end for

return result;

// Note: The body of this method could consist of one return

statement,

// if you call Arrays.copyOf

} // end toArray

/** Sees whether this bag is empty.

@return True if this bag is empty, or false if not. */

public boolean isEmpty()

{

return numberOfEntries == 0;

} // end isEmpty

/** Gets the current number of entries in this bag.

@return The integer number of entries currently in this bag. */

public int getCurrentSize()

{

return numberOfEntries;

} // end getCurrentSize

/** Counts the number of times a given entry appears in this bag.

@param anEntry The entry to be counted.

@return The number of times anEntry appears in this ba. */

public int getFrequencyOf(T anEntry)

{

checkInitialization();

int counter = 0;

for (int index = 0; index < numberOfEntries; index++)

{

if (anEntry.equals(bag[index]))

{

counter++;

} // end if

} // end for

return counter;

} // end getFrequencyOf

/** Tests whether this bag contains a given entry.

@param anEntry The entry to locate.

@return True if this bag contains anEntry, or false otherwise. */

public boolean contains(T anEntry)

{

checkInitialization();

return getIndexOf(anEntry) > -1; // or >= 0

} // end contains

/** Removes all entries from this bag. */

public void clear()

{

while (!isEmpty())

remove();

} // end clear

/** Removes one unspecified entry from this bag, if possible.

@return Either the removed entry, if the removal

was successful, or null. */

public T remove()

{

checkInitialization();

T result = removeEntry(numberOfEntries - 1);

return result;

} // end remove

/** Removes one occurrence of a given entry from this bag.

@param anEntry The entry to be removed.

@return True if the removal was successful, or false if not. */

public boolean remove(T anEntry)

{

checkInitialization();

int index = getIndexOf(anEntry);

T result = removeEntry(index);

return anEntry.equals(result);

} // end remove

// Returns true if the array bag is full, or false if not.

private boolean isArrayFull()

{

return numberOfEntries >= bag.length;

} // end isArrayFull

// Locates a given entry within the array bag.

// Returns the index of the entry, if located,

// or -1 otherwise.

// Precondition: checkInitialization has been called.

private int getIndexOf(T anEntry)

{

int where = -1;

boolean found = false;

int index = 0;

while (!found && (index < numberOfEntries))

{

if (anEntry.equals(bag[index]))

{

found = true;

where = index;

} // end if

index++;

} // end while

// Assertion: If where > -1, anEntry is in the array bag, and it

// equals bag[where]; otherwise, anEntry is not in the array.

return where;

} // end getIndexOf

// Removes and returns the entry at a given index within the array.

// If no such entry exists, returns null.

// Precondition: 0 <= givenIndex < numberOfEntries.

// Precondition: checkInitialization has been called.

private T removeEntry(int givenIndex)

{

T result = null;

if (!isEmpty() && (givenIndex >= 0))

{

result = bag[givenIndex]; // Entry to remove

int lastIndex = numberOfEntries - 1;

bag[givenIndex] = bag[lastIndex]; // Replace entry to remove

with last entry

bag[lastIndex] = null; // Remove reference to last

entry

numberOfEntries--;

} // end if

return result;

} // end removeEntry

// Throws an exception if this object is not initialized.

private void checkInitialization()

{

if (!initialized)

throw new SecurityException("ArrayBag object is not initialized

properly.");

} // end checkInitialization

} // end ArrayBag