vue+springboot实现图形验证码Kaptcha的示例

	  <el-form-item prop="verificationCode" label="验证码" style="text-align: left;">
		  <el-input v-model="form.verificationCode" placeholder="请输入验证码" style="width: 120px;vertical-align: top;"></el-input>
		  <img id="img" alt="验证码" @click="refreshCode" :src="form.imgCodeUrl" style="padding-left: 12px;"/>
	  </el-form-item>

    data() {
      return {
        form: {
          username: '',
          password: '',
		  verificationCode:'',
		  imgCodeUrl:this.$verificationCodeUrl,
        },
    ...
	...
  refreshCode(){
	  this.form.imgCodeUrl=this.$verificationCodeUrl+"?d="+new Date().getTime();
  }	

//验证码地址
Vue.prototype.$verificationCodeUrl="http://127.0.0.1/api/createImageCode";

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

...
import java.util.Properties;
 
@Configuration
public class KaptchaConfig {
    @Bean
    public DefaultKaptcha getDefaultKaptcha() {
        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        Properties properties = new Properties();
        // 图片宽
        properties.setProperty("kaptcha.image.width", "130");
        // 图片高
        properties.setProperty("kaptcha.image.height", "50");
        // 图片边框
        properties.setProperty("kaptcha.border", "yes");
        // 边框颜色
        properties.setProperty("kaptcha.border.color", "105,179,90");
        // 字体颜色
        properties.setProperty("kaptcha.textproducer.font.color", "blue");
        // 字体大小
        properties.setProperty("kaptcha.textproducer.font.size", "40");
        // session key
        properties.setProperty("kaptcha.session.key", "imageCode");
        // 验证码长度
        properties.setProperty("kaptcha.textproducer.char.length", "4");
        // 字体
        properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");
        Config config = new Config(properties);
        defaultKaptcha.setConfig(config);
        return defaultKaptcha;
    }
}

	...
	@Autowired
	private DefaultKaptcha defaultKaptcha;
	...
	//生成图片验证码
	@GetMapping("/createImageCode")
	public void createImageCode(HttpServletRequest request,HttpServletResponse response) {
		response.setHeader("Cache-Control", "no-store, no-cache");
		response.setContentType("image/jpeg");
		// 生成文字验证码
		String text = defaultKaptcha.createText();
		// 生成图片验证码
		BufferedImage image = defaultKaptcha.createImage(text);
		//保存到session域
		HttpSession session = request.getSession();
		session.setAttribute("imageCode",text);
		ServletOutputStream out = null;
		try {
			//响应输出图片流
			out = response.getOutputStream();
			ImageIO.write(image, "jpg", out);
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				out.flush();
				out.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

      submitForm() {
        this.$refs.form.validate(valid => {
		  //表单校验通过
          if (valid) {
			//先判断图形验证码
			this.$http.get("/verifyImageCode",{params:{verificationCode:this.form.verificationCode}})
			.then((response)=>{
				//图形验证码成功
				if(response.data.code === 0){
					//判断用户名和密码
					this.$http.post("/user/login",{
						username:this.form.username,
						password:this.form.password
					})
					.then((response)=>{
						if(response.data.code === 0){//登录成功
							this.$message({
							  message: '登录成功',
							  type: 'success',
							});
							localStorage.setItem("user",JSON.stringify(response.data.data));//保存用户信息
							this.$router.push("/");
						}
						else{
							this.$message.error("用户名或密码错误，请重试！！！");
						}
					})
					.catch((error)=>{
						//未接受到response的网络传输等错误
						console.log(error);
					});
				}else{//图形验证码错误
					this.$message.error(response.data.data.message);
					return;
				}
			})
			.catch((error)=>{
				//未接受到response的网络传输等错误
				console.log(error);
				return;
			});	
          } else {
            this.$message.error('表单填写错误，请检查');
            return false;
          }
        });
      },

	//匹对图片验证码
	@GetMapping("/verifyImageCode")
	public CommonResult<Object> verifyImageCode(String verificationCode,HttpServletRequest request) {
		HttpSession session = request.getSession();
		if(session.getAttribute("imageCode").equals(verificationCode)) {
			return CommonResult.success();
		}else {
			return CommonResult.failed(ErrorCode.IMG_CODE_VERIFY_ERROR.getCode(), Message.createMessage(ErrorCode.IMG_CODE_VERIFY_ERROR.getMessage()));
		}
	}

//携带证书 session id
axios.defaults.withCredentials = true

//配置跨域过滤器CorsFilter
@Configuration
public class CorsConfig {
    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        //允许证书
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.setAllowCredentials(true);
        List<String> list = Arrays.asList("*");
        corsConfiguration.setAllowedHeaders(list);
        corsConfiguration.setAllowedMethods(list);
        corsConfiguration.setAllowedOriginPatterns(list);
        source.registerCorsConfiguration("/**", corsConfiguration);
        CorsFilter corsFilter = new CorsFilter(source);
        return corsFilter;
    }
}

#获取同一个session id的cookie设置
server.servlet.session.cookie.secure=true
server.servlet.session.cookie.same-site=none