SpringBoot使用谷歌方式生成图片验证码

1.新建一个springboot的项目

2.导入坐标

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

3.编写配置

1）颜色配置类

package com.zys.springboottestexample.common.kaptcha;

import org.assertj.core.util.Lists;

import java.awt.*;
import java.util.List;
import java.util.Random;

/**
 * 验证码颜色
 */
public class KaptchaColor {

    public static Color getColor() {

        List<Color> colors = Lists.newArrayList();
        colors.add(new Color(0, 135, 255));
        colors.add(new Color(51, 153, 51));
        colors.add(new Color(255, 102, 102));
        colors.add(new Color(255, 153, 0));
        colors.add(new Color(153, 102, 0));
        colors.add(new Color(153, 102, 153));
        colors.add(new Color(51, 153, 153));
        colors.add(new Color(102, 102, 255));
        colors.add(new Color(0, 102, 204));
        colors.add(new Color(204, 51, 51));
        colors.add(new Color(128, 153, 65));
        Random random = new Random();
        int colorIndex = random.nextInt(10);
        return colors.get(colorIndex);
    }
}

2）降噪配置

package com.zys.springboottestexample.common.kaptcha;

import com.google.code.kaptcha.NoiseProducer;
import com.google.code.kaptcha.util.Configurable;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 验证码加噪处理
 */
public class KaptchaNoise extends Configurable implements NoiseProducer {
    public KaptchaNoise() {
    }

    @Override
    public void makeNoise(BufferedImage image, float factorOne, float factorTwo, float factorThree, float factorFour) {

        int width = image.getWidth();
        int height = image.getHeight();
        Graphics2D graph = (Graphics2D)image.getGraphics();
        graph.setRenderingHints(new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON));
        graph.setStroke(new BasicStroke(1.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));
        Random random = new Random();
        int noiseLineNum = random.nextInt(3);
        if(noiseLineNum == 0){
            noiseLineNum = 1;
        }
        for (int i = 0; i < noiseLineNum; i++){
            graph.setColor(KaptchaColor.getColor());
            graph.drawLine(random.nextInt(width), random.nextInt(height), 10 + random.nextInt(20), 10 + random.nextInt(20));
        }

        graph.dispose();
    }
}

3）字体配置

package com.zys.springboottestexample.common.kaptcha;

import com.google.code.kaptcha.util.Configurable;

import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.font.GlyphVector;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 验证码字体生成（根据文字内容）
 */
public class KaptchaWordRenderer extends Configurable implements com.google.code.kaptcha.text.WordRenderer {

    public KaptchaWordRenderer() {
    }

    @Override
    public BufferedImage renderWord(String word, int width, int height) {
        int fontSize = this.getConfig().getTextProducerFontSize();
        Font[] fonts = this.getConfig().getTextProducerFonts(fontSize);
        int charSpace = this.getConfig().getTextProducerCharSpace();
        BufferedImage image = new BufferedImage(width, height, 2);

        Graphics2D g2D = image.createGraphics();
        g2D.setColor(Color.WHITE);
        RenderingHints hints = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        hints.add(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
        g2D.setRenderingHints(hints);
        g2D.setStroke(new BasicStroke(1.0f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));

        FontRenderContext frc = g2D.getFontRenderContext();
        Random random = new Random();
        int startPosY = (height - fontSize) / 5 + fontSize;
        char[] wordChars = word.toCharArray();
        Font[] chosenFonts = new Font[wordChars.length];
        int[] charWidths = new int[wordChars.length];
        int widthNeeded = 0;

        int startPosX;
        for(startPosX = 0; startPosX < wordChars.length; ++startPosX) {
            chosenFonts[startPosX] = fonts[random.nextInt(fonts.length)];
            char[] charToDraw = new char[]{wordChars[startPosX]};
            GlyphVector gv = chosenFonts[startPosX].createGlyphVector(frc, charToDraw);
            charWidths[startPosX] = (int)gv.getVisualBounds().getWidth();
            if (startPosX > 0) {
                widthNeeded += 2;
            }

            widthNeeded += charWidths[startPosX];
        }

        startPosX = (width - widthNeeded) / 2;

        for(int i = 0; i < wordChars.length; ++i) {
            g2D.setColor(KaptchaColor.getColor());
            g2D.setFont(chosenFonts[i].deriveFont(Font.PLAIN));
            char[] charToDraw = new char[]{wordChars[i]};
            g2D.drawChars(charToDraw, 0, charToDraw.length, startPosX, startPosY);
            startPosX = startPosX + charWidths[i] + charSpace;
        }

        return image;
    }

}

4）验证码主要配置

package com.zys.springboottestexample.config;

import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
import com.zys.springboottestexample.common.kaptcha.KaptchaNoise;
import com.zys.springboottestexample.common.kaptcha.KaptchaWordRenderer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Properties;

/**
 * 谷歌图片验证码配置
 */
@Configuration
public class KaptchaConfig {

    @Bean
    public DefaultKaptcha getDefaultKaptcha() {
        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        Properties properties = new Properties();
        //图片是否有边框
        properties.setProperty("kaptcha.border", "no");
        //图片的边框颜色
        properties.setProperty("kaptcha.border.color", "34,114,200");
        //图片的大小
        properties.setProperty("kaptcha.image.width", "125");
        properties.setProperty("kaptcha.image.height", "45");
        //文字内容
        properties.setProperty("kaptcha.textproducer.char.length", "5");
        //图片背景颜色
        properties.setProperty("kaptcha.background.clear.from", "white");
        properties.setProperty("kaptcha.background.clear.to", "white");

        properties.setProperty("kaptcha.word.impl", KaptchaWordRenderer.class.getName());
        properties.setProperty("kaptcha.noise.impl", KaptchaNoise.class.getName());

        Config config = new Config(properties);
        defaultKaptcha.setConfig(config);
        return defaultKaptcha;
    }

}

4.编写接口

@RestController
@RequestMapping("/kaptcha")
public class KaptchaController {

    @Autowired
    private DefaultKaptcha defaultKaptcha;

    @GetMapping("/img")
    public void createImg(HttpServletResponse response) throws IOException {
        //生成验证码文字
        String kaptchaText = defaultKaptcha.createText();
        System.out.println(kaptchaText);
        //根据文字生成图片
        BufferedImage image = defaultKaptcha.createImage(kaptchaText);
        ImageIO.write(image, "jpg", response.getOutputStream());
    }

}

5.测试

启动项目，访问http://localhost:8080/kaptcha/img就可以看到图片。

说明：对于图片，也可以使用流的方式返回给前端，然后前端直接使用img标签，把数据给src属性即可。修改后的代码如下

 　　　　//生成验证码文字
        String kaptchaText = defaultKaptcha.createText();
        System.out.println(kaptchaText);
        //根据文字生成图片
        BufferedImage image = defaultKaptcha.createImage(kaptchaText);
        ByteArrayOutputStream outputStream =new ByteArrayOutputStream();
        ImageIO.write(image, "jpg", outputStream);
        String base64Code = Base64.encodeBase64String(outputStream.toByteArray());
        return base64Code;