The document discusses implementing an interface in Java. It notes that when implementing an interface, all abstract methods in the interface must be defined in the implementing class. It then provides an example class called PartialArrayMultiset that implements the Collection interface, defining some of the abstract methods like add(), clear(), and removeAtIndex() while leaving others such as containsAll() unfinished.

1. When ever you impelemented an interface we must define the abstract methods in that interface
in inheritance class. so that we must define the all methods in that interface (collection)
solved problem:
import java.util.Collection;
import java.util.Iterator;
public class PartialArrayMultiset implements Collection
{
protected E[] _store;
protected int _size;
protected long _modCount;
public PartialArrayMultiset()
{
_modCount=0;
clear();
}
public void clear()
{
_store=(E[])(new Object[16]);
_size=0;
_modCount+=1;
}
public boolean add(E e)
{
if(_size==_store.length)
return false;
_store[_size]=e;
_size++;
return true;
}
public void removeAtIndex(int i)
{
if(i<0 || i>= _size)
throw new ArrayIndexOutOfBoundsException(i);
E oldValue=_store[i];
for(int hole=i;hole<_size-1;hole++)

2. _store[hole]=_store[hole+1];
_store[_size-1]=null;
_size--;
}
public boolean contains(Object obj)
{
return false;
}
public boolean addAll(Collection arg0) {
// TODO Auto-generated method stub
return false;
}
public boolean containsAll(Collection arg0) {
// TODO Auto-generated method stub
return false;
}
public boolean isEmpty() {
// TODO Auto-generated method stub
return false;
}
public Iterator iterator() {
// TODO Auto-generated method stub
return null;
}
public boolean remove(Object arg0) {
// TODO Auto-generated method stub
return false;
}
public boolean removeAll(Collection arg0) {
// TODO Auto-generated method stub

3. return false;
}
public boolean retainAll(Collection arg0) {
// TODO Auto-generated method stub
return false;
}
public int size() {
// TODO Auto-generated method stub
return 0;
}
public Object[] toArray() {
// TODO Auto-generated method stub
return null;
}
public T[] toArray(T[] arg0) {
// TODO Auto-generated method stub
return null;
}
}
now use this program and test run y
Solution
When ever you impelemented an interface we must define the abstract methods in that interface
in inheritance class. so that we must define the all methods in that interface (collection)
solved problem:
import java.util.Collection;
import java.util.Iterator;
public class PartialArrayMultiset implements Collection
{
protected E[] _store;
protected int _size;

4. protected long _modCount;
public PartialArrayMultiset()
{
_modCount=0;
clear();
}
public void clear()
{
_store=(E[])(new Object[16]);
_size=0;
_modCount+=1;
}
public boolean add(E e)
{
if(_size==_store.length)
return false;
_store[_size]=e;
_size++;
return true;
}
public void removeAtIndex(int i)
{
if(i<0 || i>= _size)
throw new ArrayIndexOutOfBoundsException(i);
E oldValue=_store[i];
for(int hole=i;hole<_size-1;hole++)
_store[hole]=_store[hole+1];
_store[_size-1]=null;
_size--;
}
public boolean contains(Object obj)
{
return false;
}
public boolean addAll(Collection arg0) {

5. // TODO Auto-generated method stub
return false;
}
public boolean containsAll(Collection arg0) {
// TODO Auto-generated method stub
return false;
}
public boolean isEmpty() {
// TODO Auto-generated method stub
return false;
}
public Iterator iterator() {
// TODO Auto-generated method stub
return null;
}
public boolean remove(Object arg0) {
// TODO Auto-generated method stub
return false;
}
public boolean removeAll(Collection arg0) {
// TODO Auto-generated method stub
return false;
}
public boolean retainAll(Collection arg0) {
// TODO Auto-generated method stub
return false;
}
public int size() {
// TODO Auto-generated method stub

6. return 0;
}
public Object[] toArray() {
// TODO Auto-generated method stub
return null;
}
public T[] toArray(T[] arg0) {
// TODO Auto-generated method stub
return null;
}
}
now use this program and test run y