引入依赖

<dependency><groupId>com.github.whvcse</groupId><artifactId>easy-captcha</artifactId><version>1.6.2</version>
</dependency>

代码实现

package com.qiangesoft.captcha.controller;import com.wf.captcha.*;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;/*** 验证码接口** @author qiangesoft* @date 2024-05-11*/
@RequestMapping("/captcha")
@RestController
public class MyCaptchaController {// 验证码文本类型public static final int TYPE_DEFAULT = 1;  // 字母数字混合public static final int TYPE_ONLY_NUMBER = 2;  // 纯数字public static final int TYPE_ONLY_CHAR = 3;  // 纯字母public static final int TYPE_ONLY_UPPER = 4;  // 纯大写字母public static final int TYPE_ONLY_LOWER = 5;  // 纯小写字母public static final int TYPE_NUM_AND_UPPER = 6;  // 数字大写字母/*** 数字验证码*/@GetMapping("/arithmetic")public void arithmetic(HttpServletResponse response) throws IOException {setResponse(response, "arithmetic.jpg");ArithmeticCaptcha arithmeticCaptcha = new ArithmeticCaptcha(150, 65);arithmeticCaptcha.setLen(3);arithmeticCaptcha.out(response.getOutputStream());}/*** 中文验证码*/@GetMapping("/chinese")public void chinese(HttpServletResponse response) throws IOException {setResponse(response, "chinese.jpg");ChineseCaptcha chineseCaptcha = new ChineseCaptcha(150, 65);chineseCaptcha.setLen(4);chineseCaptcha.out(response.getOutputStream());}/*** 中文gif验证码*/@GetMapping("/chineseGif")public void chineseGif(HttpServletResponse response) throws IOException {setResponse(response, "chineseGif.gif");ChineseGifCaptcha chineseGifCaptcha = new ChineseGifCaptcha(150, 65);chineseGifCaptcha.setLen(4);chineseGifCaptcha.out(response.getOutputStream());}/*** gif验证码*/@GetMapping("/gif")public void gif(HttpServletResponse response) throws IOException {setResponse(response, "gif.gif");GifCaptcha gifCaptcha = new GifCaptcha(150, 65);gifCaptcha.setLen(4);gifCaptcha.setCharType(TYPE_ONLY_NUMBER);gifCaptcha.out(response.getOutputStream());}/*** 英文字母验证码*/@GetMapping("/spec")public void spec(HttpServletResponse response) throws IOException {setResponse(response, "spec.jpg");SpecCaptcha specCaptcha = new SpecCaptcha(150, 65);specCaptcha.setLen(4);specCaptcha.out(response.getOutputStream());}/*** 设置响应信息** @param response* @param fileName*/private void setResponse(HttpServletResponse response, String fileName) {response.setContentType("application/octet-stream;charset=utf-8");response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(fileName, StandardCharsets.UTF_8));}
}

测试