First inject dependencies in pom.xml
<dependency>
<groupId>com.github.penggle</groupId>
<artifactId>kaptcha</artifactId>
<version>2.3.2</version>
</dependency>
Then we need to declare the DefaultKaptcha bean object in the configuration file.
Then we can find a directory and create a class called CaptchaGenerator.java
to specifically handle the logic of generating verification codes.
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;
@Autowired
public 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();
}
}
Then declare the CaptchaGenerator object in the class that writes the interface.
Note that you must use the constructor method to assign values
, otherwise you will not be able to get things.
private CaptchaGenerator captchaGenerator;
@Autowired
public BookController(CaptchaGenerator captchaGenerator) {
this.captchaGenerator = captchaGenerator;
}
Finally write the function
@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();
}
Then we directly access the port + interface prefix/captcha to access the verification code. The verification
code content I set here is 3922. You can modify it according to the situation. It is usually random.