导入依赖

<dependency>
    <groupId>com.github.axet</groupId>
    <artifactId>kaptcha</artifactId>
    <version>0.0.9</version>
</dependency>

配置

@Configuration
public class KaptchaConfig {
    @Bean
    public DefaultKaptcha producer() {
        Properties properties = new Properties();
        properties.put("kaptcha.border", "no");
        properties.put("kaptcha.textproducer.font.color", "black");
        properties.put("kaptcha.textproducer.char.space", "4");
        Config config = new Config(properties);
        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        defaultKaptcha.setConfig(config);
        return defaultKaptcha;
    }
}

使用示例

（1）引入对象

@Autowired
private Producer producer;

（2）获取参数和图片

//生成文字，并缓存起来
String code = producer.createText();
//生成图片，响应到页面
BufferedImage img = producer.createImage(code);
//响应到页面
response.setHeader("Cache-Control", "no-store, no-cache");
response.setContentType("image/png");
ServletOutputStream out = response.getOutputStream();
ImageIO.write(img, "png", out);
IOUtils.closeQuietly(out);