Simple example of an iterable in Java that behaves similar to Python 3's "range" iterator.

Range.java

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

public class Range implements Iterable<Integer> {
    private int start, end;

    public Range(int start, int end) {
        this.start = start;
        this.end = end;
    }

    @Override
    public Iterator<Integer> iterator() {
        return new RangeIterator();
    }

    // Inner class example
    private class RangeIterator implements
                    Iterator<Integer> {
        private int cursor;

        public RangeIterator() {
            this.cursor = Range.this.start;
        }

        @Override
        public boolean hasNext() {
            return this.cursor < Range.this.end;
        }

        @Override
        public Integer next() {
            if(this.hasNext()) {
                int current = cursor;
                cursor ++;
                return current;
            }
            throw new NoSuchElementException();
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }
    }


    public static void main(String[] args) {
        Range range = new Range(1, 10);

        // Long way
        Iterator<Integer> it = range.iterator();
        while(it.hasNext()) {
            int cur = it.next();
            System.out.println(cur);
        }

        // Shorter, nicer way:
        // Read ":" as "in"
        for(Integer cur : range) {
            System.out.println(cur);
        }
    }
}