Java生成图片验证码

手动实现图片验证码生成

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;

public class VerificationCode {

    private static Random random = new Random(7);

    /**
     * 指定色系范围随机生成颜色 ，随机公式  RGB =  fc + random.nextInt(Math.abs(bc - fc))
     * @param fc
     * @param bc
     * @return
     */
    private static Color getRandColor(int fc, int bc) {
        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int temp = Math.abs(bc - fc);
        int r = fc + random.nextInt(temp);
        int g = fc + random.nextInt(temp);
        int b = fc + random.nextInt(temp);
        return new Color(r, g, b);
    }

    /**
     * 随机生成一个颜色数值
     * @return
     */
    private static int getRandomIntColor() {
        int[] rgb = getRandomRgb();
        int color = 0;
        for (int c : rgb) {
            color = color << 8;
            color = color | c;
        }
        return color;
    }

    /**
     * 随机生成三原色并返回
     * @return
     */
    private static int[] getRandomRgb() {
        int[] rgb = new int[3];
        for (int i = 0; i < 3; i++) {
            rgb[i] = random.nextInt(255);
        }
        return rgb;
    }

    /**
     * 将图片内容扭曲
     * @param g
     * @param w1
     * @param h1
     * @param color
     */
    private static void shear(Graphics g, int w1, int h1, Color color) {
        shearX(g, w1, h1, color);
        shearY(g, w1, h1, color);
    }

    private static void shearX(Graphics g, int w1, int h1, Color color) {

        int period = random.nextInt(2);

        boolean borderGap = true;
        int frames = 1;
        int phase = random.nextInt(2);

        for (int i = 0; i < h1; i++) {
            double d = (double) (period >> 1)
                    * Math.sin((double) i / (double) period
                    + (6.2831853071795862D * (double) phase)
                    / (double) frames);
            g.copyArea(0, i, w1, 1, (int) d, 0);
            if (borderGap) {
                g.setColor(color);
                g.drawLine((int) d, i, 0, i);
                g.drawLine((int) d + w1, i, w1, i);
            }
        }

    }

    private static void shearY(Graphics g, int w1, int h1, Color color) {

        int period = random.nextInt(40) + 10; // 50;

        boolean borderGap = true;
        int frames = 20;
        int phase = 7;
        for (int i = 0; i < w1; i++) {
            double d = (double) (period >> 1)
                    * Math.sin((double) i / (double) period
                    + (6.2831853071795862D * (double) phase)
                    / (double) frames);
            g.copyArea(i, 0, 1, h1, 0, (int) d);
            if (borderGap) {
                g.setColor(color);
                g.drawLine(i, (int) d, i, 0);
                g.drawLine(i, (int) d + h1, i, h1);
            }

        }

    }

    /**
     * 获取验证码图片
     * @param w 图片宽度
     * @param h 图片高度
     * @param os 图片保存的流
     * @param code  验证码
     * @throws IOException
     */
    public static void getCodeImage(int w, int h, OutputStream os, String code) throws IOException {
        BufferedImage bufferedImage = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
        Graphics2D graphics2D = bufferedImage.createGraphics();
        graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);

        Color[] colors = new Color[5];
        Color[] colorSpaces = new Color[] { Color.WHITE, Color.CYAN,
                Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
                Color.PINK, Color.YELLOW };
        float[] fractions = new float[colors.length];
        for(int i = 0; i < colors.length; i++){
            colors[i] = colorSpaces[random.nextInt(colorSpaces.length)];
            fractions[i] = random.nextFloat();
        }
        Arrays.sort(fractions);

        graphics2D.setColor(Color.GRAY);// 设置边框色
        graphics2D.fillRect(0, 0, w, h);

        // 随机颜色并设置背景色
        Color randColor = getRandColor(200, 250);
        graphics2D.setColor(randColor);// 设置背景色
        graphics2D.fillRect(0, 2, w, h-4);

        //绘制干扰线
        graphics2D.setColor(getRandColor(0, 255));// 设置线条的颜色
        for (int i = 0; i < 15; i++) {
            int x = 0;
            int y = random.nextInt(h - 1);
            int xl = w - 1;
            int yl = random.nextInt(w - 1);
            graphics2D.drawLine(x, y, xl, yl);
        }

        // 添加噪点
        float yawpRate = 0.05f;// 噪声率
        int area = (int) (yawpRate * w * h);
        for (int i = 0; i < area; i++) {
            int x = random.nextInt(w);
            int y = random.nextInt(h);
            int rgb = getRandomIntColor();
            bufferedImage.setRGB(x, y, rgb);
        }

        shear(graphics2D, w, h, randColor);// 使图片扭曲

        int verifySize = 4;
        graphics2D.setColor(getRandColor(100, 160));
        int fontSize = h-4;
        // 设置字体
        Font font = new Font("Algerian", Font.ITALIC, fontSize);
        graphics2D.setFont(font);
        char[] chars = code.toCharArray();
        for(int i = 0; i < verifySize; i++){
            AffineTransform affine = new AffineTransform();
            affine.setToRotation(Math.PI / 4 * random.nextDouble() * (random.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize/2, h/2);
            graphics2D.setTransform(affine);
            graphics2D.drawChars(chars, i, 1, ((w-10) / verifySize) * i + 5, h/2 + fontSize/2 - 10);
        }

        graphics2D.dispose();
        ImageIO.write(bufferedImage, "jpg", os);
    }

}

调用演示

 OutputStream os = new FileOutputStream("/home/test.jpg");
        VerificationCode.getCodeImage(90, 30, os, "anca");