注解实现Controller从header中解析Jwt并注入到参数中

场景需求为： gateway给header中存了jwt，jwt存了多个信息，可能有角色，uid，权限等，需要一个注解，在Controller上，使用@JwtClaimParam("userId") Long userId 将jwt中的userId解析出来并注入Controller参数的userId中。

1. 定义注解

import java.lang.annotation.*;
/**
* @author : eben@hi.want.net
* @date : 2023/7/6 17:34
* @description:
*/
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface JwtClaimParam {
String value() default "";
}

2. 拦截注解

package net.want.common.annotation.handler;

import cn.hutool.jwt.JWT;
import cn.hutool.jwt.JWTUtil;
import net.want.common.annotation.JwtClaimParam;
import org.springframework.core.MethodParameter;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;

import java.util.List;

/**
 * @author : eben@hi.want.net
 * @date : 2023/7/7 15:19
 * @description:
 */
public class ProcessedHeaderArgumentResolver implements HandlerMethodArgumentResolver {

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.getParameterAnnotation(JwtClaimParam.class) != null;
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
        JwtClaimParam annotation = parameter.getParameterAnnotation(JwtClaimParam.class);
        String claimName = StringUtils.hasText(annotation.value()) ? annotation.value() : parameter.getParameterName();
        String token = webRequest.getHeader("jwt");

        // 解析JWT并获取声明值
        JWT jwt = JWTUtil.parseToken(token);
        Class<?> dynamicClass = Class.forName(parameter.getParameter().getParameterizedType().getTypeName());
        Object convertedValue = jwt.getPayload(claimName);
        if (dynamicClass.equals(List.class)) {
            convertedValue = List.of(parameter);
        } else {
            // 普通类型， INT , LONG, String 之类的
            convertedValue = dynamicClass.getDeclaredMethod("valueOf", String.class).invoke(null, convertedValue.toString());
        }
        return convertedValue;
    }

}

其中 convertedValue = dynamicClass.getDeclaredMethod("valueOf", String.class).invoke(null, convertedValue.toString());
意义为： 执行dynamicClass的valueOf方法，对应的入参是convertedValue.toString()，入参类型是 String.class

这里只实现了 对于List和Int，Long，String等基本类型，不知道怎么全自动反射。

3. 将拦截器注入WebConfig

@Configuration
public class WebConfig implements WebMvcConfigurer {

    /**
     * 注册自定义的参数解析器
     */
    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers){
        argumentResolvers.add(new RequestStringParamHandlerMethodArgumentResolver());
        argumentResolvers.add(new ProcessedHeaderArgumentResolver());
        WebMvcConfigurer.super.addArgumentResolvers(argumentResolvers);

    }
}

4. 任意Controller上使用

public ResultVO<list> userUploadFile(MultipartFile[] files, @JwtClaimParam("userId") Long userId)</list

ps:Gateway中添加jwt代码如下

                    webclientBuilder.build()
                            .get()
                            .uri("lb://xxxxxxxx/open/auth/api/auth/user/info")
                            .header("token", token)
                            .exchange()
                            .flatMap(resp -> resp.bodyToMono(ResultVO.class)
                                    .doOnSuccess(
                                            body -> {
                                                System.out.println("success");
                                                System.out.println(body);
                                                UserInfoResponse userInfoResponse = new UserInfoResponse();
                                                BeanUtil.copyProperties(body.getData(), userInfoResponse);
                                                if (body.getCode() != null && ResultCode.SUCCESS.getCode().equals(body.getCode()) && body.getData() != null) {
                                                    Optional.ofNullable(userInfoResponse.getId()).map(i -> exchange.getRequest().mutate().header("userId", i.toString()));
                                                    HashMap<String, Object> tokenMap = new HashMap<>();
                                                    tokenMap.put("userId", userInfoResponse.getId());
                                                    String jwt = JWT.create()
                                                                    .setPayload("userId", userInfoResponse.getId())
                                                                    .setKey("testRes".getBytes())
                                                                    .sign();
                                                    exchange.getRequest().mutate().header("jwt", jwt);
                                                } else {
                                                    log.error("获取admin-uid失败-1, 考虑token是否过期/正确");
                                                    throw new RuntimeException("获取admin-uid失败");
                                                }
                                            }
                                    ))
                            .doOnError(i -> {
                                log.error("获取admin-uid失败-2, 考虑token是否过期/正确");
                                throw new RuntimeException("获取admin-uid失败");
                            })
                            .block();