萌新求助，求JAVA版树莓派UNL2003驱动28BYJ-48步进电机完整程序

/*
基于树莓派3b+开发
*/

import com.pi4j.io.gpio.GpioController;
import com.pi4j.io.gpio.GpioFactory;
import com.pi4j.io.gpio.GpioPinDigitalOutput;
import com.pi4j.io.gpio.PinState;
import com.pi4j.io.gpio.RaspiPin;

import java.util.Scanner;

public class test
{
   //获取全局Gpio 引脚控制器对象
   public static final GpioController gpio = GpioFactory.getInstance();
        //定义编号为00/01/02/03引脚为数字输出引脚，初始化为低电平
        public static final GpioPinDigitalOutput pin1output = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_00, "" ,PinState.LOW);
        public static final GpioPinDigitalOutput pin2output = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_01, "" ,PinState.LOW);
        public static final GpioPinDigitalOutput pin3output = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_02, "" ,PinState.LOW);
        public static final GpioPinDigitalOutput pin4output = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_03, "" ,PinState.LOW);

        public static void forward (int step)
        {
                s