Java实现验证码

最终效果

实现思路

使用BufferedImage用于在内存中存储生成的验证码图片
使用Graphics来进行验证码图片的绘制，并将绘制在图片上的验证码存放到session中用于后续验证
最后通过ImageIO将生成的图片进行输出
通过页面提交的验证码和存放在session中的验证码对比来进行校验

实现思路是拷贝别人的： https://blog.csdn.net/worm0527/article/details/51030864

算术验证码

控制层实现：

public static final String SESSION_CODE_KEY_1 = "SESSION_KEY_IMAGE_CODE_1";

/**
 * 模拟用户登录时的数字算数验证码
 * @param response
 * @return
 */
@RequestMapping(value="/verifyCode", method= RequestMethod.GET)
@ResponseBody
public void getVerifyCode(HttpServletRequest request,HttpServletResponse response) {
    try {
        ImageCode imageCode = testService.createVerifyCode(request);
        //存入session
        request.getSession().setAttribute(SESSION_CODE_KEY_1,imageCode);

        ImageIO.write(imageCode.getImage(), "JPEG", response.getOutputStream());
    }catch(Exception e) {}
}

服务层实现：

/**
 * Created by xingyuchao on 2018/4/23.
 */
@Service
public class TestService {

    @Autowired
    CodeProperties codeProperties;

    //定义运算符
    private static char[] ops = new char[] {'+', '-', '*'};

    /**
     * 生成验证码
     * @return
     */
    public ImageCode createVerifyCode(HttpServletRequest request) {

        //create the image
        BufferedImage image = new BufferedImage(codeProperties.getWidth(), codeProperties.getHeight(), BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        // set the background color
        g.setColor(new Color(0xDCDCDC));
        g.fillRect(0, 0, codeProperties.getWidth(), codeProperties.getHeight());
        // draw the border
        g.setColor(Color.black);
        g.drawRect(0, 0, codeProperties.getWidth() - 1, codeProperties.getHeight() - 1);
        // create a random instance to generate the codes
        Random rdm = new Random();
        // make some confusion
        for (int i = 0; i < 50; i++) {
            int x = rdm.nextInt(codeProperties.getWidth());
            int y = rdm.nextInt(codeProperties.getHeight());
            g.drawOval(x, y, 0, 0);
        }
        // generate a random code
        String verifyCode = generateVerifyCode(rdm);
        g.setColor(new Color(0, 100, 0));
        g.setFont(new Font("Candara", Font.BOLD, 24));
        g.drawString(verifyCode, 8, 24);
        g.dispose();
        //计算验证码结果
        int rnd = calc(verifyCode);
        //将运算结果存到redis中
        //redisService.set("verifyCode:"+user.getId(),60, rnd);
        //输出图片
        return new ImageCode(image, rnd+"", codeProperties.getExpireIn());
    }

    
    /**
     * 4+2-7  组合算数
     * + - *
     * */
    private static String generateVerifyCode(Random rdm) {
        int num1 = rdm.nextInt(10);
        int num2 = rdm.nextInt(10);
        int num3 = rdm.nextInt(10);
        char op1 = ops[rdm.nextInt(3)];
        char op2 = ops[rdm.nextInt(3)];
        String exp = ""+ num1 + op1 + num2 + op2 + num3;
        return exp;
    }



    /**
     * 计算结果
     * @param exp
     * @return
     */
    private static int calc(String exp) {
        try {
            ScriptEngineManager manager = new ScriptEngineManager();
            ScriptEngine engine = manager.getEngineByName("JavaScript");
            return (Integer)engine.eval(exp);
        }catch(Exception e) {
            return 0;
        }
    }



    public static void main(String[] args) {
        //System.out.println(calc("8*8"));

        System.out.println(generateVerifyCode(new Random()));
    }
    
}

通用属性设置：

/**
 * 配置文件信息
 * 默认配置
 */
@Data
@Component
@ConfigurationProperties(prefix = "dxh.code")
public class CodeProperties {

    /*图片验证码宽度*/
    private int width = 70;

    /*图片验证码高度*/
    private int height = 30;

    /*图片验证码长度4位*/
    private int length = 4;

    /*图片验证码默认过期时间*/
    private int expireIn = 60;
}

普通验证码

控制层实现：

public static final String SESSION_CODE_KEY_2 = "SESSION_KEY_IMAGE_CODE_2";
/**
 * 普通验证码
 * @param request
 * @param response
 * @throws IOException
 */
@GetMapping("/image")
public void createCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
    //生成图片验证码
    ImageCode imageCode = testService.generate(request);

    //存入session
    request.getSession().setAttribute(SESSION_CODE_KEY_2,imageCode);

    //将生成的图片写到响应中
    ImageIO.write(imageCode.getImage(),"JPEG",response.getOutputStream());
}

服务层实现：

public ImageCode generate(HttpServletRequest request) {
    int width = ServletRequestUtils.getIntParameter(request, "width",
            codeProperties.getWidth());
    int height = ServletRequestUtils.getIntParameter(request, "height",
            codeProperties.getHeight());
    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

    Graphics g = image.getGraphics();

    Random random = new Random();

    g.setColor(getRandColor(200, 250));
    g.fillRect(0, 0, width, height);
    g.setFont(new Font("Times New Roman", Font.ITALIC, 20));
    g.setColor(getRandColor(160, 200));
    for (int i = 0; i < 155; i++) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(12);
        int yl = random.nextInt(12);
        g.drawLine(x, y, x + xl, y + yl);
    }

    String sRand = "";
    for (int i = 0; i < codeProperties.getLength(); i++) {
        String rand = String.valueOf(random.nextInt(10));
        sRand += rand;
        g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
        g.drawString(rand, 13 * i + 6, 16);
    }

    g.dispose();
    return new ImageCode(image, sRand, codeProperties.getExpireIn());
}

/**
 * 生成随机背景条纹
 *
 * @param fc
 * @param bc
 * @return
 */
private Color getRandColor(int fc, int bc) {
    Random random = new Random();
    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);
}

html:

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>hello</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
    <h1 align="center">验证码测试</h1>
    <h3 align="center">算数验证码测试</h3>
    <form action="/code/checkCode" method="post">
        <table align="center">
            <tr>
                <td>算数验证码：
                <input type="text" name="code">
                <input type="hidden" name="status" value="1">
                <img src="/code/verifyCode?+"&timestamp="+new Date().getTime()">
                </td>
            </tr>
            <tr>
                <td align="center" colspan="2"><button type="submit">登录</button></td>
            </tr>
        </table>
    </form>

    <hr><hr>
    <h3 align="center">普通验证码测试</h3>
    <form action="/code/checkCode" method="post">
        <table align="center">
            <tr>
                <td>普通验证码：
                    <input type="text" name="code">
                    <input type="hidden" name="status" value="2">
                    <img src="/code/image?+"&timestamp="+new Date().getTime()">
                </td>
            </tr>
            <tr>
                <td align="center" colspan="2"><button type="submit">登录</button></td>
            </tr>
        </table>
    </form>
</body>
</html>

---------------------------------------------------------------------------------------

上面的代码写的有点垃圾，不可扩展，简单的做了下修改

增加校验器接口，一个项目中可以这段时间使用这个验证码，过段时间又换了一种验证码

/**
 * 校验码生成器接口
 * Created by xingyuchao on 2017/12/19.
 *
 */
public interface ValidateCodeGenerator {

   /**
     * 生成校验码
    * @param request
    * @return
    */
   ImageCode generate(HttpServletRequest request);
   
}

将两种验证码实现方式抽离出来

/**
 * Created by xingyuchao on 2018/4/26.
 * 算术验证码, 默认生成方式
 */
@Component("codeGenerator")
public class ArithmeticCodeGenerator implements  ValidateCodeGenerator {

    @Autowired
    private CodeProperties codeProperties;

    //定义运算符
    private static char[] ops = new char[] {'+', '-', '*'};

    /**
     * 生成验证码
     * @return
     */
    @Override
    public ImageCode generate(HttpServletRequest request) {

        //create the image
        BufferedImage image = new BufferedImage(codeProperties.getWidth(), codeProperties.getHeight(), BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        // set the background color
        g.setColor(new Color(0xDCDCDC));
        g.fillRect(0, 0, codeProperties.getWidth(), codeProperties.getHeight());
        // draw the border
        g.setColor(Color.black);
        g.drawRect(0, 0, codeProperties.getWidth() - 1, codeProperties.getHeight() - 1);
        // create a random instance to generate the codes
        Random rdm = new Random();
        // make some confusion
        for (int i = 0; i < 50; i++) {
            int x = rdm.nextInt(codeProperties.getWidth());
            int y = rdm.nextInt(codeProperties.getHeight());
            g.drawOval(x, y, 0, 0);
        }
        // generate a random code
        String verifyCode = generateVerifyCode(rdm);
        g.setColor(new Color(0, 100, 0));
        g.setFont(new Font("Candara", Font.BOLD, 24));
        g.drawString(verifyCode, 8, 24);
        g.dispose();
        //计算验证码结果
        int rnd = calc(verifyCode);
        //将运算结果存到redis中
        //redisService.set("verifyCode:"+user.getId(),60, rnd);
        //输出图片
        return new ImageCode(image, rnd+"", codeProperties.getExpireIn());
    }


    /**
     * 4+2-7  组合算数
     * + - *
     * */
    private static String generateVerifyCode(Random rdm) {
        int num1 = rdm.nextInt(10);
        int num2 = rdm.nextInt(10);
        int num3 = rdm.nextInt(10);
        char op1 = ops[rdm.nextInt(3)];
        char op2 = ops[rdm.nextInt(3)];
        String exp = ""+ num1 + op1 + num2 + op2 + num3;
        return exp;
    }



    /**
     * 计算结果
     * @param exp
     * @return
     */
    private static int calc(String exp) {
        try {
            ScriptEngineManager manager = new ScriptEngineManager();
            ScriptEngine engine = manager.getEngineByName("JavaScript");
            return (Integer)engine.eval(exp);
        }catch(Exception e) {
            return 0;
        }
    }


    public static void main(String[] args) {
        //System.out.println(calc("8*8"));
        System.out.println(generateVerifyCode(new Random()));
    }
}

/**
 * Created by xingyuchao on 2018/4/26.
 * 普通验证码
 */
public class ImageCodeGenerator implements ValidateCodeGenerator {

    @Autowired
    CodeProperties codeProperties;

    @Override
    public ImageCode generate(HttpServletRequest request) {
        int width = ServletRequestUtils.getIntParameter(request, "width",
                codeProperties.getWidth());
        int height = ServletRequestUtils.getIntParameter(request, "height",
                codeProperties.getHeight());
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        Graphics g = image.getGraphics();

        Random random = new Random();

        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Times New Roman", Font.ITALIC, 20));
        g.setColor(getRandColor(160, 200));
        for (int i = 0; i < 155; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }

        String sRand = "";
        for (int i = 0; i < codeProperties.getLength(); i++) {
            String rand = String.valueOf(random.nextInt(10));
            sRand += rand;
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            g.drawString(rand, 13 * i + 6, 16);
        }

        g.dispose();
        return new ImageCode(image, sRand, codeProperties.getExpireIn());
    }

    /**
     * 生成随机背景条纹
     *
     * @param fc
     * @param bc
     * @return
     */
    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        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);
    }


    public CodeProperties getCodeProperties() {
        return codeProperties;
    }

    public void setCodeProperties(CodeProperties codeProperties) {
        this.codeProperties = codeProperties;
    }
}

增加扩展配置

/**
 * 验证码相关的扩展点配置。配置在这里的bean，业务系统都可以通过声明同类型或同名的bean来覆盖默认的配置。
 * Created by xingyuchao on 2018/04/26.
 *
 */
@Configuration
public class ValidateCodeBeanConfig {

    @Autowired
   private CodeProperties codeProperties;
   
   /**
    * 图片验证码图片生成器
    * @return
    */
   @Bean
   @ConditionalOnMissingBean(name = "codeGenerator")
   public ValidateCodeGenerator codeGenerator() {
      ImageCodeGenerator codeGenerator = new ImageCodeGenerator(); 
      codeGenerator.setCodeProperties(codeProperties);
      return codeGenerator;
   }

}

这样子，换验证方式的时候，只需要将ArithmeticCodeGenerator上的注解注释掉就行

最终效果

实现思路

算术验证码

普通验证码

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