Vector.java

package org.fmz.container;

public abstract class Vector{

	protected Object[] data;
	protected static final int DEFAULT_CAPACITY = 100;
	protected int numItems;



	public void finalize() throws Throwable {
		super.finalize();
	}

	public Vector(){
		data = new Object[DEFAULT_CAPACITY] ;
	}

	/**
	 * 
	 * @param element
	 */
	public abstract boolean append(Object element) ;

	public void clear(){
		for(int i=0; i<numItems; i++){
			data[i] = null ;
		}
		numItems = 0 ;
	}

	/**
	 * 
	 * @param element
	 */
	public boolean contains(Object element){
		return indexOf(element) != -1 ;
	}

	/**
	 * 
	 * @param index
	 */
	public Object elementAt(int index){
		if(index < 0 || index > numItems-1)
			return null;
		return data[index] ;
	}

	/**
	 * 
	 * @param element
	 */
	public int indexOf(Object element){
		for(int i=0; i<numItems; i++)
			if(element.equals(data[i]))
				return i ;
		return -1 ;
	}

	/**
	 * 
	 * @param index
	 * @param element
	 */
	public abstract boolean insertAt(int index, Object element) ;

	public boolean isEmpty(){
		return numItems == 0 ;
	}

	public boolean isFull(){
		return numItems == data.length ;
	}

	/**
	 * 
	 * @param element
	 */
	public boolean remove(Object element){
		int pos = indexOf(element) ;
		if(pos == -1)
			return false;
		removeAt(pos) ;
		return true ;
	}

	/**
	 * 
	 * @param index
	 */
	public Object removeAt(int index){
		if(index < 0 || index > numItems-1)
			return null ;
		Object temp = data[index] ;
		while(index < numItems-1)
			data[index] = data[index+1] ;
			index ++ ;
		data[--numItems] = null ;
		return temp ;
	}

	/**
	 * 
	 * @param index
	 * @param element
	 */
	public boolean replace(int index, Object element){
		if(index < 0 || index > numItems-1)
			return false;
		data[index] = element ;
		return true ;
	}

	public int size(){
		return numItems ;
	}

}