Dynamic Generic Array

DynamicArray.java

import java.util.Iterator;

public class DynamicArray<I> implements Iterable<I> {
    class ArrayIterator implements Iterator<I> {
        
        int bookmark = 0;
        @Override
        public boolean hasNext() {
            return bookmark<size()-1;
        }

        @Override
        public I next() {
            return get(bookmark++);
        }
    }

    private int size      = 0;
    private I[] dynamisch = null;

    @SuppressWarnings("unchecked")
    public DynamicArray() {
        dynamisch = (I[]) new Object[2];
    }

    public int size() {
        return this.size;
    }

    public int capacity() {
        return dynamisch.length;
    }

    public I get(int pos) {
        if (pos < 0) {
            pos = 0;
        }
        if (pos > dynamisch.length) {
            throw new IllegalArgumentException();
        } else {
            return this.dynamisch[pos];
        }
    }

    @SuppressWarnings("unchecked")
    private void increaseCapacityRshift() {
        I[] x = (I[]) new Object[capacity() * 2];
        System.arraycopy(dynamisch, 0, x, 1, size);
        dynamisch = x;
    }

    @SuppressWarnings("unchecked")
    private void increaseCapacityNoshift() {
        I[] x = (I[]) new Object[capacity() * 2];
        System.arraycopy(dynamisch, 0, x, 0, size);
        dynamisch = x;
    }

    private void keepCapacityRshift() {
        System.arraycopy(dynamisch, 0, dynamisch, 1, size);
    }

    public void addFirst(I e) {
        if (size >= capacity()) {
            increaseCapacityRshift();
        } else {
            keepCapacityRshift();
        }
        dynamisch[0] = e;
        size++;
    }

    public void addLast(I e) {
        if (size >= capacity()) {
            increaseCapacityNoshift();
        }
        dynamisch[size] = e; 
        size++;
    }

    public I removeFirst() {
        I deleted = dynamisch[0];
        for (int i = 0; i < size; i++) {
            dynamisch[i] = dynamisch[i + 1];
        }
        size--;
        return deleted;
    }

    public I removeLast() {
        I deleted = dynamisch[size - 1];
        dynamisch[--size] = null;
        return deleted;
    }

    @Override
    public ArrayIterator iterator() {
        return new ArrayIterator();
    }
}