FilteredIterator

FilteredIterator

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

public class FilteredIterator<T> implements Iterator<T>, Iterable<T> {
    private Iterator<T> iterator;
    private boolean hasNext;
    private Predicate<T> predicate;
    private T obj;


    public FilteredIterator(Iterator<T> iterator, Predicate<T> predicate) {
        this.iterator = iterator;
        this.predicate = predicate;
        setNextObject();
    }

    public FilteredIterator(T[] array, Predicate<T> predicate) {
        if(array!=null && array.length!=0){
            this.iterator = Arrays.asList(array).iterator();
            this.predicate = predicate;
        }else{
            this.iterator=null;
            this.predicate=predicate;
        }
        setNextObject();
    }


    @Override
    public Iterator<T> iterator() {
        return this;
    }

    @Override
    public boolean hasNext() {
        return hasNext;
    }

    @Override
    public T next() {
        if(!hasNext){
            throw new NoSuchElementException("No more element...");
        }
        T prevObject = obj;
        setNextObject();
        return prevObject;
    }

    @Override
    public void remove() {
        throw new UnsupportedOperationException("Remove not supported");
    }

    private void setNextObject(){
        hasNext = false;
        if(iterator!=null){
            while (iterator.hasNext()){
                T object = iterator.next();
                if(predicate.validate(object)){
                    obj = object;
                    hasNext = true;
                    break;
                }
            }
        }
    }
    public static interface Predicate<E>{
        boolean validate(E obj);
    }
}