Need help for array linear list program in java.

package data_structures;

import java.util.Iterator;
import java.util.NoSuchElementException;

public interface LinearListADT extends Iterable {
public static final int DEFAULT_MAX_CAPACITY = 100;

// Adds the Object obj to the end of list.
public void addLast(E obj);

// Adds the Object obj to the beginning of list.
public void addFirst(E obj);

// Inserts the Object obj at the position indicated. If there is an element at
// that location, all elements from that location to the end of the list are
// shifted down to make room for the new insertion. The location is one based.
// If the location > size()+1 then a RuntimeException is thrown. List elements // must be contiguous.
public void insert(E obj, int location);

// Removes and returns the object located at the parameter location (one based).
// Throws a RuntimeException if the location does not map to a valid position within the list.
public E remove(int location);

// Removes and returns the parameter object obj from the list if the list contains it, null otherwise.
// The ordering of the list is preserved. The list may contain duplicate elements. This method
// removes and returns the first matching element found when traversing the list from first position.
public E remove(E obj);

// Removes and returns the parameter object obj in first position in list if the list is not empty,
// null if the list is empty. The ordering of the list is preserved.
public E removeFirst();

// Removes and returns the parameter object obj in last position in list if the list is not empty,
// null if the list is empty. The ordering of the list is preserved.
public E removeLast();

// Returns the parameter object located at the parameter location position (one based).
// Throws a RuntimeException if the location does not map to a valid position within the list.
public E get(int location);

// Returns true if the parameter object obj is in the list, false otherwise.
public boolean contains(E obj);

// Returns the one based location of the parameter object obj if it is in the list, -1 otherwise.
// In the case of duplicates, this method returns the element closest to position #1.
public int locate(E obj);

// The list is returned to an empty state.
public void clear();

// Returns true if the list is empty, otherwise false
public boolean isEmpty();

// Returns the number of Objects currently in the list.
public int size();

// Returns an Iterator of the values in the list, presented in
// the same order as the underlying order of the list. (position #1 first)
public Iterator iterator();

}