Implement ArraySet

package example.array;

import java.io.Serializable;

import java.util.AbstractSet;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Iterator;

import java.util.Set;

public class ArraySet extends AbstractSet implements Cloneable, Serializable {

    private ArrayList list;

    public ArraySet() {

	list = new ArrayList();

    }

    public ArraySet(Collection col) {

	list = new ArrayList();

	// No need to check for dups if col is a set

	Iterator itor = col.iterator();

	if (col instanceof Set) {

	    while (itor.hasNext()) {

		list.add(itor.next());

	    }

	} else {

	    while (itor.hasNext()) {

		add(itor.next());

	    }

	}

    }

    public Iterator iterator() {

	return list.iterator();

    }

    public int size() {

	return list.size();

    }

    public boolean add(Object element) {

	boolean modified;

	if (modified = !list.contains(element)) {

	    list.add(element);

	}

	return modified;

    }

    public boolean remove(Object element) {

	return list.remove(element);

    }

    public boolean isEmpty() {

	return list.isEmpty();

    }

    public boolean contains(Object element) {

	return list.contains(element);

    }

    public void clear() {

	list.clear();

    }

    public Object clone() {

	try {

	    ArraySet newSet = (ArraySet) super.clone();

	    newSet.list = (ArrayList) list.clone();

	    return newSet;

	} catch (CloneNotSupportedException e) {

	    throw new InternalError();

	}

    }

    public static void main(String args[]) {

	String elements[] = { "Java", "Source", "and", "Support", "." };

	Set set = new ArraySet(Arrays.asList(elements));

	Iterator iter = set.iterator();

	while (iter.hasNext()) {

	    System.out.println(iter.next());

	}

    }

}