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目录

一、VerifyCodeUtil

二、需要使用Base64Util 

三、控制器使用生成

一、VerifyCodeUtil

package com.baizhi.utils;

import javax.imageio.ImageIO;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;

public class VerifyCodeUtil {
    //使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符
    public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
    private static Random random = new Random();

    /**
     * 使用系统默认字符源生成验证码
     *
     * @param verifySize 验证码长度
     * @return
     */
    public static String generateVerifyCode(int verifySize) {
        return generateVerifyCode(verifySize, VERIFY_CODES);
    }

    /**
     * 使用指定源生成验证码
     *
     * @param verifySize 验证码长度
     * @param sources    验证码字符源
     * @return
     */
    public static String generateVerifyCode(int verifySize, String sources) {
        if (sources == null || sources.length() == 0) {
            sources = VERIFY_CODES;
        }
        int codesLen = sources.length();
        Random rand = new Random(System.currentTimeMillis());
        StringBuilder verifyCode = new StringBuilder(verifySize);
        for (int i = 0; i < verifySize; i++) {
            verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
        }
        return verifyCode.toString();
    }

    /**
     * 生成指定数据的验证码并以Base64编码一字符串形式返回，用于前后分离
     * @param w
     * @param h
     * @param code
     * @return
     * @throws IOException
     */
    public static String outputImage(int w, int h, String code) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        VerifyCodeUtil.outputImage(100, 39, baos, code);
        final String BASE64_IMAGE = "data:image/jpeg;base64,%s";
        String base64Img = String.format(BASE64_IMAGE, Base64Util.encode(baos.toByteArray()));
        return base64Img;
    }


    /**
     * 生成指定验证码图像文件
     *
     * @param w
     * @param h
     * @param outputFile
     * @param code
     * @throws IOException
     */
    public static void outputImage(int w, int h, File outputFile, String code) throws IOException {
        if (outputFile == null) {
            return;
        }
        File dir = outputFile.getParentFile();
        if (!dir.exists()) {
            dir.mkdirs();
        }
        try {
            outputFile.createNewFile();
            FileOutputStream fos = new FileOutputStream(outputFile);
            outputImage(w, h, fos, code);
            fos.close();
        } catch (IOException e) {
            throw e;
        }
    }

    /**
     * 输出指定验证码图片流
     *
     * @param w
     * @param h
     * @param os
     * @param code
     * @throws IOException
     */
    public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {
        int verifySize = code.length();
        BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Random rand = new Random();
        Graphics2D g2 = image.createGraphics();
        g2.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[rand.nextInt(colorSpaces.length)];
            fractions[i] = rand.nextFloat();
        }
        Arrays.sort(fractions);

        g2.setColor(Color.GRAY);// 设置边框色
        g2.fillRect(0, 0, w, h);

        Color c = getRandColor(200, 250);
        g2.setColor(c);// 设置背景色
        g2.fillRect(0, 2, w, h - 4);

        //绘制干扰线
        Random random = new Random();
        g2.setColor(getRandColor(160, 200));// 设置线条的颜色
        for (int i = 0; i < 20; i++) {
            int x = random.nextInt(w - 1);
            int y = random.nextInt(h - 1);
            int xl = random.nextInt(6) + 1;
            int yl = random.nextInt(12) + 1;
            g2.drawLine(x, y, x + xl + 40, y + yl + 20);
        }

        // 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();
            image.setRGB(x, y, rgb);
        }

        shear(g2, w, h, c);// 使图片扭曲

        g2.setColor(getRandColor(100, 160));
        int fontSize = h - 6;
        Font font = new Font("Algerian", Font.ITALIC, fontSize);
        g2.setFont(font);
        char[] chars = code.toCharArray();
        for (int i = 0; i < verifySize; i++) {
            AffineTransform affine = new AffineTransform();
            affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);
            g2.setTransform(affine);
            g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
        }

        g2.dispose();
        ImageIO.write(image, "jpg", os);
    }


    private static Color getRandColor(int fc, int bc) {
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

    private static int getRandomIntColor() {
        int[] rgb = getRandomRgb();
        int color = 0;
        for (int c : rgb) {
            color = color << 8;
            color = color | c;
        }
        return color;
    }

    private static int[] getRandomRgb() {
        int[] rgb = new int[3];
        for (int i = 0; i < 3; i++) {
            rgb[i] = random.nextInt(255);
        }
        return rgb;
    }

    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);
            }
        }
    }

    public static void main(String[] args) throws IOException {
        File dir = new File("D:/upload/verifyCode");
        int w = 200, h = 80;
        for (int i = 0; i < 50; i++) {
            String verifyCode = generateVerifyCode(4);
            File file = new File(dir, verifyCode + ".jpg");
            outputImage(w, h, file, verifyCode);
        }
    }
}

二、需要使用Base64Util 

package com.baizhi.utils;

import com.alibaba.druid.util.StringUtils;
import org.apache.commons.net.util.Base64;

import java.io.UnsupportedEncodingException;

/**
 * @describe: base64工具类
 * @author: jiahong.xing/
 * @version: v1.0
 * @date 2018/6/27/002714:08
 */
public class Base64Util {

    /**
     * 编码
     *
     * @param str
     * @return
     */
    public static String encode(final String str) {
        if (StringUtils.isEmpty(str)) {
            return null;
        }
        return Base64.encodeBase64String(str.getBytes());
    }

    //重载
    public static String encode(byte[] binaryData) {
        return Base64.encodeBase64String(binaryData);
    }

    /**
     * 解码
     *
     * @param base64
     * @return
     */
    public static String decode(final String base64) {
        if (StringUtils.isEmpty(base64)) {
            return null;
        }
        String str = null;
        try {
            str = new String(Base64.decodeBase64(base64), "UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return str;
    }

    //解码
    public static byte[] decodeBite(String encodedText) {
        byte[] bytes = Base64.decodeBase64(encodedText);

        return bytes;
    }

    //重载
    public static String decode(byte[] binaryData) {
        String str = null;
        try {
            str = new String(Base64.decodeBase64(binaryData), "UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return str;
    }

    /**
     * 判断是否base64过的原文，原理为解密再加密，得到原字符串则代表的是已加密过的
     *
     * @param base64
     * @return
     */
    public static boolean isBase64(final String base64) {
        if (StringUtils.isEmpty(base64)) {
            return false;
        }
        String de = decode(base64);

        String en = encode(de).replaceAll("[\\s*\t\n\r]", "");

        return base64.equals(en);
    }

    //上面的相反判断
    public static boolean isNotBase64(final String base64) {
        return !isBase64(base64);
    }


    //得到一个base64文件的实际大小
    public static long base64file_size(String base64String) {
        //1.获取base64字符串长度(不含data:audio/wav;base64,文件头)
        int size0 = base64String.length();

        //2.获取字符串的尾巴的最后10个字符，用于判断尾巴是否有等号，正常生成的base64文件'等号'不会超过4个
        String tail = base64String.substring(size0 - 10);

        //3.找到等号，把等号也去掉,(等号其实是空的意思,不能算在文件大小里面)
        int equalIndex = tail.indexOf("=");
        if (equalIndex > 0) {
            size0 = size0 - (10 - equalIndex);
        }

        //4.计算后得到的文件流大小，单位为字节
        return size0 - ((long) size0 / 8) * 2;
    }
}

三、控制器使用生成

    /*生成验证码*/
    @RequestMapping("generateImageCode")
    public void generateImageCode(HttpSession session, HttpServletResponse response) throws IOException {
        /*1、生产随机数
         * 2、保存随机数到Session中
         * 3、将随机数字符串生成图片
         * 4、通过response相应图片
         * */
        //1、生产随机数
        String code = VerifyCodeUtil.generateVerifyCode(4);
        //2、存到session中
        session.setAttribute("code", code);
        //3、生成图片 4、通过相应输出流响应图片
        //响应类型
        response.setContentType("image/png");
        //响应输出流
        ServletOutputStream os = response.getOutputStream();
        //生成图片
        VerifyCodeUtil.outputImage(80, 40, os, code);


    }