Spring Boot2.7生成用于登录的图片验证码

先在 pom.xml 注入依赖

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

然后需要在配置文件中声明一下DefaultKaptcha 的 bean对象
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然后我们随便找个目录创建一个类叫CaptchaGenerator.java
专门处理生成验证码的逻辑

import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Properties;@Component
public class CaptchaGenerator {private DefaultKaptcha defaultKaptcha;@Autowiredpublic CaptchaGenerator(DefaultKaptcha defaultKaptcha) {this.defaultKaptcha = defaultKaptcha;}public byte[] generateCaptchaImage(String captchaText) throws IOException {Properties properties = new Properties();properties.setProperty("kaptcha.textproducer.char.string", "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890");properties.setProperty("kaptcha.textproducer.char.length", "4");Config config = new Config(properties);defaultKaptcha.setConfig(config);BufferedImage captchaImage = defaultKaptcha.createImage(captchaText);ByteArrayOutputStream outputStream = new ByteArrayOutputStream();ImageIO.write(captchaImage, "jpg", outputStream);return outputStream.toByteArray();}
}

然后在写接口的类中声明一下CaptchaGenerator 的对象
注意这里要用构造方法赋值
否则东西会拿不到
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private CaptchaGenerator captchaGenerator;@Autowired
public BookController(CaptchaGenerator captchaGenerator) {this.captchaGenerator = captchaGenerator;
}

最后编写函数

@GetMapping(value = "/captcha", produces = MediaType.IMAGE_JPEG_VALUE)
public void getCaptchaImage(HttpServletResponse response) throws IOException {String captchaText = "3922";// 生成验证码文本byte[] captchaImage = captchaGenerator.generateCaptchaImage(captchaText);response.setContentType(MediaType.IMAGE_JPEG_VALUE);response.getOutputStream().write(captchaImage);response.getOutputStream().flush();
}