如何在java spring中从identityServer4中提取jwk

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-oauth2-client</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-oauth2-jose</artifactId>
</dependency>

spring:
  security:
    oauth2:
      client:
        provider:
          identityserver:
            issuer-uri: <IdentityServer4的URL>
        registration:
          identityserver:
            client-id: <客户端ID>
            client-secret: <客户端密钥>

import org.springframework.core.convert.converter.Converter;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.RequestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.security.oauth2.core.OAuth2TokenValidator;
import org.springframework.security.oauth2.core.OAuth2TokenValidatorResult;
import org.springframework.security.oauth2.core.OAuth2TokenType;
import org.springframework.security.oauth2.jwt.Jwt;
import org.springframework.security.oauth2.jwt.JwtDecoder;
import org.springframework.security.oauth2.jwt.JwtDecoders;
import org.springframework.security.oauth2.jwt.JwtValidators;
import org.springframework.security.oauth2.jwt.NimbusJwtDecoder;
import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationConverter;
import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationToken;
import org.springframework.security.oauth2.server.resource.web.BearerTokenResolver;
import org.springframework.security.web.authentication.AuthenticationConverter;
import org.springframework.security.web.authentication.AuthenticationFilter;
import org.springframework.security.web.authentication.AuthenticationSuccessHandler;
import org.springframework.security.web.authentication.SimpleUrlAuthenticationSuccessHandler;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.filter.OncePerRequestFilter;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URI;
import java.util.Collections;
import java.util.List;
import java.util.Map;

public class JwkSetEndpointFilter extends OncePerRequestFilter {

    private static final String DEFAULT_JWK_SET_ENDPOINT = "/.well-known/jwks.json";
    private static final String DEFAULT_JWK_SET_URI = "/.well-known/openid-configuration";

    private final RestTemplate restTemplate;
    private final String jwkSetEndpoint;
    private final JwtDecoder jwtDecoder;

    public JwkSetEndpointFilter() {
        this.restTemplate = new RestTemplate();
        this.jwkSetEndpoint = DEFAULT_JWK_SET_ENDPOINT;
        this.jwtDecoder = createJwtDecoder(DEFAULT_JWK_SET_URI);
    }

    public JwkSetEndpointFilter(String jwkSetEndpoint, String jwkSetUri) {
        Assert.hasText(jwkSetEndpoint, "jwkSetEndpoint must not be empty");
        Assert.hasText(jwkSetUri, "jwkSetUri must not be empty");
        this.restTemplate = new RestTemplate();
        this.jwkSetEndpoint = jwkSetEndpoint;
        this.jwtDecoder = createJwtDecoder(jwkSetUri);
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        String requestUri = request.getRequestURI();
        if (requestUri.endsWith(jwkSetEndpoint)) {
            ResponseEntity<Map> responseEntity = restTemplate.exchange(RequestEntity.get(URI.create(jwkSetEndpoint)).build(), Map.class);
            Map<String, Object> jwkSet = responseEntity.getBody();
            response.setContentType(MediaType.APPLICATION_JSON_VALUE);
            response.getWriter().write(jwkSet.toString());
        } else {
            filterChain.doFilter(request, response);
        }
    }

    private JwtDecoder createJwtDecoder(String jwkSetUri) {
        ResponseEntity<Map> responseEntity = restTemplate.exchange(RequestEntity.get(URI.create(jwkSetUri)).build(), Map.class);
        Map<String, Object> jwkSetUriResponse = responseEntity.getBody();
        List<Map<String, Object>> keys = (List<Map<String, Object>>) jwkSetUriResponse.get("keys");
        NimbusJwtDecoder jwtDecoder = JwtDecoders.fromIssuerLocation(jwkSetUri);
        jwtDecoder.setJwtValidator(createJwtValidator(keys));
        return jwtDecoder;
    }

    private OAuth2TokenValidator<Jwt> createJwtValidator(List<Map<String, Object>> keys) {
        List<OAuth2TokenValidator<Jwt>> validators = Collections.singletonList(JwtValidators.createDefault());
        return new DelegatingOAuth2TokenValidator<>(validators);
    }
}

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class SecurityConfig {

    @Bean
    public FilterRegistrationBean<JwkSetEndpointFilter> jwkSetEndpointFilter() {
        FilterRegistrationBean<JwkSetEndpointFilter> registrationBean = new FilterRegistrationBean<>();
        registrationBean.setFilter(new JwkSetEndpointFilter());
        registrationBean.addUrlPatterns("/.well-known/jwks.json");
        return registrationBean;
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.oauth2.jwt.Jwt;
import org.springframework.security.oauth2.jwt.JwtDecoder;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MyController {

    private final JwtDecoder jwtDecoder;

    @Autowired
    public MyController(JwtDecoder jwtDecoder) {
        this.jwtDecoder = jwtDecoder;
    }

    @GetMapping("/decode")
    public Jwt decodeJwt(String token) {
        return jwtDecoder.decode(token);
    }
}