Iterator - 순환 구조 만들기

When Using It

Heavy한 Job이 수행되는 클래스들을 미리 만들어 놓고 공유하고 싶을때

Class Diagram 
 

Sample Code



public interface Aggregate {

}

public interface Iterator {

public Object next();

public boolean hasNext();

}

public class ConcreteAggregate implements Aggregate {

private Object[] items;

public Iterator iterator() {

return new ConcreteIterator(this);

}

public Object getItem(int index) {

if ( index < items.length - 1)

return items[index];

else 

return null;

}

public int getLength() {

return items.length;

}

}

public class ConcreteIterator implements Iterator {

private ConcreteAggregate aggregate;

private int index;

public ConcreteIterator(ConcreteAggregate aggregate) {

this.aggregate = aggregate;

this.index = 0;

}

@Override

public Object next() {

Object item = aggregate.getItem(index);

if ( item != null ) {

index++;

}

return item;

}

@Override

public boolean hasNext() {

if ( index < aggregate.getLength()) {

return true;

} else {

return false;

}

}

}

Caution

특별한 주의사항은 없다.