How do test whether the queue is full?

[rocafella5007]

// Queue.java
// demonstrates queue
// to run this program: C>java QueueApp
////////////////////////////////////////////////////////////////
public class Queue
{
private int maxSize;
private long[] queArray;
private int front;
private int rear;
private int nItems;
//--------------------------------------------------------------
public Queue(int s) // constructor
{
maxSize = s;
queArray = new long[maxSize];
front = 0;
rear = -1;
nItems = 0;
}
//--------------------------------------------------------------
public void insert(long item) // insert item
{
int j;

if(nItems==0) // if no items,
queArray[nItems++] = item; // insert at 0
else // if items,
{
for(j=nItems-1; j>=0; j--) // start at end,
{
if( item > queArray[j] ) // if new item larger,
queArray[j+1] = queArray[j]; // shift upward
else // if smaller,
break; // done shifting
} // end for
queArray[j+1] = item; // insert it
nItems++;
} // end else (nItems > 0)
} // end insert()
//--------------------------------------------------------------
public long remove() // take item from front of queue
{
long temp = queArray[front++]; // get value and incr front
if(front == maxSize) // deal with wraparound
front = 0;
nItems--; // one less item
return temp;
}
//--------------------------------------------------------------
public long peekFront() // peek at front of queue
{
return queArray[front];
}
//--------------------------------------------------------------
public boolean isEmpty() // true if queue is empty
{
return (nItems==0);
}
//--------------------------------------------------------------
public boolean isFull() // true if queue is full
{
return (nItems==maxSize);
}
//--------------------------------------------------------------
public int size() // number of items in queue
{
return nItems;
}
//-------------------------------------------------------------
public long getNum(int index) //get the conents of the queue
{
return queArray[index];
}

} // end class Queue
class QueueApp
{
public static void main(String[] args)
{
Queue theQueue = new Queue(5); // queue holds 5 items

theQueue.insert(10); // insert 4 items
theQueue.insert(20);
theQueue.insert(30);
theQueue.insert(40);

theQueue.remove(); // remove 3 items
theQueue.remove(); // (10, 20, 30)
theQueue.remove();

theQueue.insert(50); // insert 4 more items
theQueue.insert(60); // (wraps around)
theQueue.insert(70);
theQueue.insert(80);

for (int i = 0; i < theQueue.size();i++) ///outputs the contents of the queue
{
System.out.println( theQueue.getNum(i) );
}
} // end main()
} // end class QueueApp