Java写一个输出图片验证码的类，要求参数可控

import java.awt.*;
import java.awt.image.*;
import java.io.*;
import java.util.Random;
import javax.imageio.ImageIO;

public class Captcha {
    private int width = 100;
    private int height = 50;
    private int codeCount = 4;
    private int lineCount = 20;
    private String code = null;
    private BufferedImage buffImg = null;
    private char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
            'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
            'X', 'Y', 'Z', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
    // 验证码类型为仅数字,可以根据需求修改
    // private char[] codeSequence = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };

    public Captcha() {
        this.createCode();
    }

    /**
     * @param width  图片宽
     * @param height 图片高
     */
    public Captcha(int width, int height) {
        this.width = width;
        this.height = height;
        this.createCode();
    }

    /**
     * @param width     图片宽
     * @param height    图片高
     * @param codeCount 字符个数
     * @param lineCount 干扰线条数
     */
    public Captcha(int width, int height, int codeCount, int lineCount) {
        this.width = width;
        this.height = height;
        this.codeCount = codeCount;
        this.lineCount = lineCount;
        this.createCode();
    }

    public void createCode() {
        int x = 0, fontHeight = 0, codeY = 0;
        int red = 0, green = 0, blue = 0;

        x = width / (codeCount + 2);//每个字符的宽度
        fontHeight = height - 2;//字体的高度
        codeY = height - 4;

        // 图像buffer
        buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g = buffImg.createGraphics();
        // 生成随机数
        Random random = new Random();
        // 将图像填充为白色
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, width, height);
        // 创建