java生成验证码返回前端图片，后端通过redis存储和校验

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目录

1.导入maven

2.编写config类

3.编写controller

4.验证

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1.导入maven

<dependency><groupId>com.github.penggle</groupId><artifactId>kaptcha</artifactId><version>2.3.2</version>
</dependency>

2.编写config类

CaptchaConfig  

这里使用的是：1*2=2 这样的验证形式，因此我配了一个bean名为captchaProducerMath的验证码配置。

光配置不行，我通过属性properties.setProperty设置了生成格式，也就是验证码文本器。

验证码文本器通过重写getText方法定义生成的格式。格式为10以内的+-*/

注意：验证码文本器改成自己的路径

package com.zsp.quartz.config;import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;import java.util.Properties;import static com.google.code.kaptcha.Constants.*;/*** 验证码配置*/
@Configuration
public class CaptchaConfig
{@Bean(name = "captchaProducer")public DefaultKaptcha getKaptchaBean(){DefaultKaptcha defaultKaptcha = new DefaultKaptcha();Properties properties = new Properties();// 是否有边框 默认为true 我们可以自己设置yes，noproperties.setProperty(KAPTCHA_BORDER, "yes");// 验证码文本字符颜色 默认为Color.BLACKproperties.setProperty(KAPTCHA_TEXTPRODUCER_FONT_COLOR, "black");// 验证码图片宽度 默认为200properties.setProperty(KAPTCHA_IMAGE_WIDTH, "160");// 验证码图片高度 默认为50properties.setProperty(KAPTCHA_IMAGE_HEIGHT, "60");// 验证码文本字符大小 默认为40properties.setProperty(KAPTCHA_TEXTPRODUCER_FONT_SIZE, "38");// KAPTCHA_SESSION_KEYproperties.setProperty(KAPTCHA_SESSION_CONFIG_KEY, "kaptchaCode");// 验证码文本字符长度 默认为5properties.setProperty(KAPTCHA_TEXTPRODUCER_CHAR_LENGTH, "4");// 验证码文本字体样式 默认为new Font("Arial", 1, fontSize), new Font("Courier", 1, fontSize)properties.setProperty(KAPTCHA_TEXTPRODUCER_FONT_NAMES, "Arial,Courier");// 图片样式 水纹com.google.code.kaptcha.impl.WaterRipple 鱼眼com.google.code.kaptcha.impl.FishEyeGimpy 阴影com.google.code.kaptcha.impl.ShadowGimpyproperties.setProperty(KAPTCHA_OBSCURIFICATOR_IMPL, "com.google.code.kaptcha.impl.ShadowGimpy");Config config = new Config(properties);defaultKaptcha.setConfig(config);return defaultKaptcha;}@Bean(name = "captchaProducerMath")public DefaultKaptcha getKaptchaBeanMath(){DefaultKaptcha defaultKaptcha = new DefaultKaptcha();Properties properties = new Properties();// 是否有边框 默认为true 我们可以自己设置yes，noproperties.setProperty(KAPTCHA_BORDER, "yes");// 边框颜色 默认为Color.BLACKproperties.setProperty(KAPTCHA_BORDER_COLOR, "105,179,90");// 验证码文本字符颜色 默认为Color.BLACKproperties.setProperty(KAPTCHA_TEXTPRODUCER_FONT_COLOR, "blue");// 验证码图片宽度 默认为200properties.setProperty(KAPTCHA_IMAGE_WIDTH, "160");// 验证码图片高度 默认为50properties.setProperty(KAPTCHA_IMAGE_HEIGHT, "60");// 验证码文本字符大小 默认为40properties.setProperty(KAPTCHA_TEXTPRODUCER_FONT_SIZE, "35");// KAPTCHA_SESSION_KEYproperties.setProperty(KAPTCHA_SESSION_CONFIG_KEY, "kaptchaCodeMath");// 验证码文本生成器properties.setProperty(KAPTCHA_TEXTPRODUCER_IMPL, "com.zsp.quartz.config.KaptchaTextCreator");// 验证码文本字符间距 默认为2properties.setProperty(KAPTCHA_TEXTPRODUCER_CHAR_SPACE, "3");// 验证码文本字符长度 默认为5properties.setProperty(KAPTCHA_TEXTPRODUCER_CHAR_LENGTH, "6");// 验证码文本字体样式 默认为new Font("Arial", 1, fontSize), new Font("Courier", 1, fontSize)properties.setProperty(KAPTCHA_TEXTPRODUCER_FONT_NAMES, "Arial,Courier");// 验证码噪点颜色 默认为Color.BLACKproperties.setProperty(KAPTCHA_NOISE_COLOR, "white");// 干扰实现类properties.setProperty(KAPTCHA_NOISE_IMPL, "com.google.code.kaptcha.impl.NoNoise");// 图片样式 水纹com.google.code.kaptcha.impl.WaterRipple 鱼眼com.google.code.kaptcha.impl.FishEyeGimpy 阴影com.google.code.kaptcha.impl.ShadowGimpyproperties.setProperty(KAPTCHA_OBSCURIFICATOR_IMPL, "com.google.code.kaptcha.impl.ShadowGimpy");Config config = new Config(properties);defaultKaptcha.setConfig(config);return defaultKaptcha;}
}

KaptchaTextCreator验证码文本生成器

继承DefaultTextCreator，覆盖原有的getText()方法

package com.zsp.quartz.config;import com.google.code.kaptcha.text.impl.DefaultTextCreator;import java.util.Random;/*** 验证码文本生成器*/
public class KaptchaTextCreator extends DefaultTextCreator
{private static final String[] CNUMBERS = "0,1,2,3,4,5,6,7,8,9,10".split(",");@Overridepublic String getText(){Integer result = 0;Random random = new Random();int x = random.nextInt(10);int y = random.nextInt(10);StringBuilder suChinese = new StringBuilder();int randomoperands = (int) Math.round(Math.random() * 2);if (randomoperands == 0){result = x * y;suChinese.append(CNUMBERS[x]);suChinese.append("*");suChinese.append(CNUMBERS[y]);}else if (randomoperands == 1){if (!(x == 0) && y % x == 0){result = y / x;suChinese.append(CNUMBERS[y]);suChinese.append("/");suChinese.append(CNUMBERS[x]);}else{result = x + y;suChinese.append(CNUMBERS[x]);suChinese.append("+");suChinese.append(CNUMBERS[y]);}}else if (randomoperands == 2){if (x >= y){result = x - y;suChinese.append(CNUMBERS[x]);suChinese.append("-");suChinese.append(CNUMBERS[y]);}else{result = y - x;suChinese.append(CNUMBERS[y]);suChinese.append("-");suChinese.append(CNUMBERS[x]);}}else{result = x + y;suChinese.append(CNUMBERS[x]);suChinese.append("+");suChinese.append(CNUMBERS[y]);}suChinese.append("=?@" + result);return suChinese.toString();}
}

3.编写controller

package com.zsp.quartz.controller;import cn.hutool.core.codec.Base64;
import com.google.code.kaptcha.Producer;
import com.zsp.quartz.Exception.CustomException;
import com.zsp.quartz.entity.dto.CaptchaDto;
import com.zsp.quartz.result.Result;
import com.zsp.quartz.service.Constants;
import com.zsp.quartz.util.IdUtils;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.util.FastByteArrayOutputStream;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.IOException;@RestController
@RequestMapping("/test")
@CrossOrigin
public class TestController {@Resource(name = "captchaProducerMath")private Producer captchaProducerMath;private RedisTemplate<String, String> stringRedisTemplate;/*** 生成验证码*/@GetMapping("/captchaImage")public Result<CaptchaDto> getCode() throws IOException{// 保存验证码信息String uuid =UUID.randomUUID().toString();// 存入redis的keyString verifyKey = Constants.CAPTCHA_CODE_KEY + uuid;String capStr = null, code = null;BufferedImage image = null;// 生成验证码// 生成具体的验证码信息 诸如2/2=?@1String capText = captchaProducerMath.createText();// 以@进行分割获取问题capStr = capText.substring(0, capText.lastIndexOf("@"));//以@进行分割，获取最终的实际结果
//        存入redis的值code = capText.substring(capText.lastIndexOf("@") + 1);image = captchaProducerMath.createImage(capStr);// 存入缓存   CAPTCHA_EXPIRATION验证码有效期stringRedisTemplate.opsForValue().set(verifyKey, code, Constants.CAPTCHA_EXPIRATION, TimeUnit.MINUTES);// 转换流base64信息写出FastByteArrayOutputStream os = new FastByteArrayOutputStream();try{ImageIO.write(image, "jpg", os);}catch (IOException e){return Result.fail("生成失败",new CaptchaDto());}CaptchaDto captchaDto = new CaptchaDto();captchaDto.setUuid(uuid); // c8a94873-2c18-4199-871a-c6a6bd2b5241captchaDto.setImg(Base64.encode(os.toByteArray()));return Result.success("生成成功",captchaDto);}/*** 校验验证码* @param code 验证码* @param uuid 唯一标识* @return 结果*/@PostMapping("validateCaptcha")public Result validateCaptcha(String code,String uuid){// redis的key 前端传来的String verifyKey = Constants.CAPTCHA_CODE_KEY + uuid;ValueOperations<String, String> valueOperations = stringRedisTemplate.opsForValue();String captcha = valueOperations.get(verifyKey);stringRedisTemplate.delete(verifyKey);if (captcha == null) {throw new CustomException("验证码已过期");}if (!code.equalsIgnoreCase(captcha)) {throw new CustomException("验证码不正确");}return Result.success("验证成功");}
}

 /*** 验证码 redis key*/public static final String CAPTCHA_CODE_KEY = "captcha_codes:";

4.验证

postman测试生成验证码图片

base64图片要想在浏览器显示，需要前面加上    data:image/gif;base64,

逗号不要忘了

验证码校验，输入结果和uuid

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