import java.lang.reflect.Field;
import java.util.ArrayList;

public class Test4 {
    public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException, IllegalArgumentException {

        ArrayList<String> l1 = new ArrayList<>(1000);

        for (int i = 0; i < 10; i++) {
            l1.add(Integer.toString(i));
        }
        l1.ensureCapacity(20);

// =====================================================

        Class l1Reflection = l1.getClass();
        Field[] fields = l1Reflection.getDeclaredFields();
        for (Field field : fields) {
            System.out.println(field.getName() + ";" + field.getType());
        }

        Field defaultCapacityField = l1Reflection.getDeclaredField("DEFAULT_CAPACITY");
        defaultCapacityField.setAccessible(true);
        int defaultCapacity = defaultCapacityField.getInt(l1Reflection);
        System.out.println(defaultCapacity);

        Field maxArraySizeField = l1Reflection.getDeclaredField("MAX_ARRAY_SIZE");
        maxArraySizeField.setAccessible(true);
        System.out.println(maxArraySizeField.getInt(l1Reflection));

    /*    Field sizeField = l1Reflection.getDeclaredField("size");
        sizeField.setAccessible(true);
        System.out.println(sizeField.get(l1Reflection));*/

        Field capacityField = l1Reflection.getDeclaredField("elementData");
        capacityField.setAccessible(true);
        int currentCapacity = ((Object[]) capacityField.get(l1Reflection)).length;
        System.out.println(currentCapacity);
    }
}