登录功能验证码生成工具类

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
/**
     * 生成验证码
     *
     * @return
     */

public class VerifyCodeUtils {
    private int width = 100;// 生成验证码图片的宽度
    private int height = 50;// 生成验证码图片的高度
    private String[] fontNames = { "宋体", "楷体", "隶书", "微软雅黑" };
    private Color bgColor = new Color(255, 255, 255);// 定义验证码图片的背景颜色为白色
    private Random random = new Random();
    private String codes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    private String text;// 记录随机字符串

/**
 * 获取一个随意颜色
 *
 * @return
 */
private Color randomColor() {
    int red = random.nextInt(150);
    int green = random.nextInt(150);
    int blue = random.nextInt(150);
    return new Color(red, green, blue);
}

/**
 * 获取一个随机字体
 *
 * @return
 */
private Font randomFont() {
    String name = fontNames[random.nextInt(fontNames.length)];
    int style = random.nextInt(4);
    int size = random.nextInt(5) + 24;
    return new Font(name, style, size);
}

 /**
     * 获取一个随机字符
     *
     * @return
     */
    private char randomChar() {
        return codes.charAt(random.nextInt(codes.length()));
    }

    /**
     * 创建一个空白的BufferedImage对象
     *
     * @return
     */
    private BufferedImage createImage() {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        g2.setColor(bgColor);// 设置验证码图片的背景颜色
        g2.fillRect(0, 0, width, height);
        return image;
    }

    public BufferedImage getImage() {
        BufferedImage image = createImage();
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < 4; i++) {
            String s = randomChar() + "";
            sb.append(s);
            g2.setColor(randomColor());
            g2.setFont(randomFont());
            float x = i * width * 1.0f / 4;
            g2.drawString(s, x, height - 15);
        }
        this.text = sb.toString();
        drawLine(image);
        return image;
    }

    /**
     * 绘制干扰线
     *
     * @param image
     */
    private void drawLine(BufferedImage image) {
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        int num = 5;
        for (int i = 0; i < num; i++) {
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int x2 = random.nextInt(width);
            int y2 = random.nextInt(height);
            g2.setColor(randomColor());
            g2.setStroke(new BasicStroke(1.5f));
            g2.drawLine(x1, y1, x2, y2);
        }
    }

    public String getText() {
        return text;
    }

    public static void output(BufferedImage image, OutputStream out) throws IOException {
        ImageIO.write(image, "JPEG", out);
    }
}