生成图片验证码工具类 Base64处理

加了一个转成了Base64编码。，其他的和网上一样。

public class ValidateCodeUtil {

    // 图片的宽度。
    private int width = 160;
    // 图片的高度。
    private int height = 40;
    // 验证码字符个数
    private int codeCount = 5;
    // 验证码干扰线数
    private int lineCount = 150;
    // 验证码
    private String code = null;
    // 验证码图片Buffer
    private BufferedImage buffImg = null;

    private String base64 = null;

    public String getBase64() {
        try {
            base64 = getBase64(buffImg);
        } catch (Exception e) {
            System.out.println("转换失败");
        }
        return base64;
    }

    // 验证码范围,去掉0(数字)和O(拼音)容易混淆的(小写的1和L也可以去掉,大写不用了)
    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'};

    /**
     * 默认构造函数,设置默认参数
     */
    public ValidateCodeUtil() {
        this.createCode();
    }

    /**
     * @param width  图片宽
     * @param height 图片高
     */
    public ValidateCodeUtil(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 ValidateCodeUtil(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(左右各空出一个字符)
        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();

        /*// 将图像背景填充为白色
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, width, height);*/
        // 增加下面代码使得背景透明
        buffImg = g.getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);
        g.dispose();
        g = buffImg.createGraphics();
        // 背景透明代码结束

        // 画图BasicStroke是JDK中提供的一个基本的画笔类,我们对他设置画笔的粗细，就可以在drawPanel上任意画出自己想要的图形了。
        g.setColor(new Color(255, 0, 0));
        g.setStroke(new BasicStroke(1f));
        g.fillRect(128, 128, width, height);

        // 生成随机数
        Random random = new Random();
        //设置字体类型、字体大小、字体样式　
        Font font = new Font("微软雅黑", Font.PLAIN, fontHeight);

        g.setFont(font);

        for (int i = 0; i < lineCount; i++) {
            // 设置随机开始和结束坐标
            int xs = random.nextInt(width);//x坐标开始
            int ys = random.nextInt(height);//y坐标开始
            int xe = xs + random.nextInt(width / 8);//x坐标结束
            int ye = ys + random.nextInt(height / 8);//y坐标结束

            // 产生随机的颜色值，让输出的每个干扰线的颜色值都将不同。
            red = random.nextInt(255);
            green = random.nextInt(255);
            blue = random.nextInt(255);
            g.setColor(new Color(red, green, blue));
            g.drawLine(xs, ys, xe, ye);
        }

        // randomCode记录随机产生的验证码
        StringBuffer randomCode = new StringBuffer();
        // 随机产生codeCount个字符的验证码。
        for (int i = 0; i < codeCount; i++) {
            String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]);
            // 产生随机的颜色值，让输出的每个字符的颜色值都将不同。
            red = random.nextInt(255);
            green = random.nextInt(255);
            blue = random.nextInt(255);
            //指定某种颜色
            //g.setColor(new Color(252, 145, 83));
            g.setColor(new Color(red, green, blue));
            g.drawString(strRand, (i + 1) * x, codeY);
            // 将产生的四个随机数组合在一起。
            randomCode.append(strRand);
        }
        // 将四位数字的验证码保存到Session中。
        code = randomCode.toString();
    }

    public void write(String path) throws IOException {
        OutputStream sos = new FileOutputStream(path);
        this.write(sos);
    }

    public void write(OutputStream sos) throws IOException {
        ImageIO.write(buffImg, "png", sos);
        sos.close();
    }

    public BufferedImage getBuffImg() {
        return buffImg;
    }

    public String getCode() {
        return code;
    }

    public static void main(String[] args) {
        ValidateCodeUtil vCode = new ValidateCodeUtil();
        Map<String, Object> map = new HashMap<>(16);
        map.put("code",vCode.getCode());
        map.put("image",vCode.getBase64());
        System.out.println(map);
    }

    /**
     * 转换成图片格式
     * @param buffImg
     * @return
     * @throws Exception
     */
    private static String getBase64(BufferedImage buffImg) throws Exception {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ImageIO.write(buffImg, "png", out);
        byte[] bytes = out.toByteArray();
        out.close();
        String base64bytes = "data:image/png;base64," + Base64Util.encode(bytes);
        return base64bytes;
    }
}

Base64Util

public class Base64Util {

    static private final int BASELENGTH = 128;
    static private final int LOOKUPLENGTH = 64;
    static private final int TWENTYFOURBITGROUP = 24;
    static private final int EIGHTBIT = 8;
    static private final int SIXTEENBIT = 16;
    static private final int FOURBYTE = 4;
    static private final int SIGN = -128;
    static private final char PAD = '=';
    static private final boolean fDebug = false;
    static final private byte[] base64Alphabet = new byte[BASELENGTH];
    static final private char[] lookUpBase64Alphabet = new char[LOOKUPLENGTH];


    static {
        for (int i = 0; i < BASELENGTH; ++i) {
            base64Alphabet[i] = -1;
        }
        for (int i = 'Z'; i >= 'A'; i--) {
            base64Alphabet[i] = (byte) (i - 'A');
        }
        for (int i = 'z'; i >= 'a'; i--) {
            base64Alphabet[i] = (byte) (i - 'a' + 26);
        }

        for (int i = '9'; i >= '0'; i--) {
            base64Alphabet[i] = (byte) (i - '0' + 52);
        }

        base64Alphabet['+'] = 62;
        base64Alphabet['/'] = 63;

        for (int i = 0; i <= 25; i++) {
            lookUpBase64Alphabet[i] = (char) ('A' + i);
        }

        for (int i = 26, j = 0; i <= 51; i++, j++) {
            lookUpBase64Alphabet[i] = (char) ('a' + j);
        }

        for (int i = 52, j = 0; i <= 61; i++, j++) {
            lookUpBase64Alphabet[i] = (char) ('0' + j);
        }
        lookUpBase64Alphabet[62] = (char) '+';
        lookUpBase64Alphabet[63] = (char) '/';

    }


    /**
     * base64 编码
     *
     * @param str
     * @return
     */
    public static String encoder(String str) {
        final Base64.Encoder encoder = Base64.getEncoder();
        String strEncoder = null;
        try {
            strEncoder = encoder.encodeToString(str.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return strEncoder;
    }

    /**
     * Encodes hex octects into Base64 
     *
     * @param binaryData Array containing binaryData 
     * @return Encoded Base64 array 
     */
    public static String encode(byte[] binaryData) {

        if (binaryData == null) {
            return null;
        }

        int lengthDataBits = binaryData.length * EIGHTBIT;
        if (lengthDataBits == 0) {
            return "";
        }

        int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
        int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
        int numberQuartet = fewerThan24bits != 0 ? numberTriplets + 1 : numberTriplets;
        char encodedData[] = null;

        encodedData = new char[numberQuartet * 4];

        byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;

        int encodedIndex = 0;
        int dataIndex = 0;
        if (fDebug) {
            System.out.println("number of triplets = " + numberTriplets);
        }

        for (int i = 0; i < numberTriplets; i++) {
            b1 = binaryData[dataIndex++];
            b2 = binaryData[dataIndex++];
            b3 = binaryData[dataIndex++];

            if (fDebug) {
                System.out.println("b1= " + b1 + ", b2= " + b2 + ", b3= " + b3);
            }

            l = (byte) (b2 & 0x0f);
            k = (byte) (b1 & 0x03);

            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
            byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
            byte val3 = ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);

            if (fDebug) {
                System.out.println("val2 = " + val2);
                System.out.println("k4   = " + (k << 4));
                System.out.println("vak  = " + (val2 | (k << 4)));
            }

            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[(l << 2) | val3];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[b3 & 0x3f];
        }

        // form integral number of 6-bit groups  
        if (fewerThan24bits == EIGHTBIT) {
            b1 = binaryData[dataIndex];
            k = (byte) (b1 & 0x03);
            if (fDebug) {
                System.out.println("b1=" + b1);
                System.out.println("b1<<2 = " + (b1 >> 2));
            }
            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[k << 4];
            encodedData[encodedIndex++] = PAD;
            encodedData[encodedIndex++] = PAD;
        } else if (fewerThan24bits == SIXTEENBIT) {
            b1 = binaryData[dataIndex];
            b2 = binaryData[dataIndex + 1];
            l = (byte) (b2 & 0x0f);
            k = (byte) (b1 & 0x03);

            byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
            byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);

            encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];
            encodedData[encodedIndex++] = lookUpBase64Alphabet[l << 2];
            encodedData[encodedIndex++] = PAD;
        }
        return new String(encodedData);
    }

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

}

运行实例：

{
image=　　//图片
data:image/png;base64,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
, code=　　//验证码
P3V44
}

复制image结果到浏览器：

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