如何使用WebClient从Spring BootJava客户端调用Oauth2受保护的endpoint“ServerWebExchange不能为Null”

Question

要求是使用WebClient从java客户端程序调用OAuth保护的endpoint。我使用的是使用反应对象的密码授权类型。请注意，我是反应编程模式的新手。当我调用webclient时，我得到以下错误**serverWebExchange不能为空**

        String data = webClient
                .post().uri(endPoint)
                // This will add the Authorization header with the bearer token.
                .attributes(ServerOAuth2AuthorizedClientExchangeFilterFunction.clientRegistrationId("custom"))
                .body(Mono.just(alert), Alert.class)
                .retrieve()
                .bodyToMono(String.class)
                // Block until we receive a response for a non-reactive client.
                .block();

java.lang.IllegalArgumentException: serverWebExchange cannot be null

    at org.springframework.security.oauth2.client.web.DefaultReactiveOAuth2AuthorizedClientManager.lambda$loadAuthorizedClient$9(DefaultReactiveOAuth2AuthorizedClientManager.java:102)
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    |_ checkpoint ⇢ Request to POST http://<hostname>/<protected_endpoint> [DefaultWebClient]
Stack trace:
        at org.springframework.security.oauth2.client.web.DefaultReactiveOAuth2AuthorizedClientManager.lambda$loadAuthorizedClient$9(DefaultReactiveOAuth2AuthorizedClientManager.java:102)
        at reactor.core.publisher.MonoErrorSupplied.subscribe(MonoErrorSupplied.java:70)
        at reactor.core.publisher.Mono.subscribe(Mono.java:4210)
        at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:75)
    .....
        at reactor.core.publisher.Mono.block(Mono.java:1665)
        at com.xxxxx.oauthclient.ApplicationTests.testWebClient(ApplicationTests.java:41)
    ....
        at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
        at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
        at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:69)
        at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
        at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
        at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)
    Suppressed: java.lang.Exception: #block terminated with an error
        at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:99)
        at reactor.core.publisher.Mono.block(Mono.java:1666)
        at com.xxxx.oauthclient.ApplicationTests.testWebClient(ApplicationTests.java:41)
        ....

@Configuration
public class ReactiveOAuthConfig {
    @Value("${oauth.username}") String username;
    @Value("${oauth.password}") String password;

    @Bean
    WebClient webClient(ReactiveOAuth2AuthorizedClientManager authorizedClientManager) {
        ServerOAuth2AuthorizedClientExchangeFilterFunction oauth =
                new ServerOAuth2AuthorizedClientExchangeFilterFunction(authorizedClientManager);

        return WebClient.builder()
                .filter(oauth)
                .build();
    }
    @Bean
    ReactiveOAuth2AuthorizedClientManager reactiveOAuth2AuthorizedClientManager(
            ReactiveClientRegistrationRepository clientRegistrationRepository,
            ServerOAuth2AuthorizedClientRepository authorizedClientRepository) {

        ReactiveOAuth2AuthorizedClientProvider authorizedClientProvider =
                ReactiveOAuth2AuthorizedClientProviderBuilder.builder()
                        .authorizationCode()
                        .refreshToken()
                        .password()
                        .build();
        DefaultReactiveOAuth2AuthorizedClientManager authorizedClientManager =
                new DefaultReactiveOAuth2AuthorizedClientManager(
                        clientRegistrationRepository, authorizedClientRepository);
        authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);

        // For the `password` grant, the `username` and `password` are supplied via request parameters,
        // so map it to `OAuth2AuthorizationContext.getAttributes()`.
        authorizedClientManager.setContextAttributesMapper(contextAttributesMapper());

        return authorizedClientManager;
    }

    private Function<OAuth2AuthorizeRequest, Mono<Map<String, Object>>> contextAttributesMapper() {
        return authorizeRequest -> {
            Map<String, Object> contextAttributes = Collections.emptyMap();
            if (StringUtils.hasText(username) && StringUtils.hasText(password)) {
                contextAttributes = new HashMap<>();

                // `PasswordOAuth2AuthorizedClientProvider` requires both attributes
                contextAttributes.put(OAuth2AuthorizationContext.USERNAME_ATTRIBUTE_NAME, username);
                contextAttributes.put(OAuth2AuthorizationContext.PASSWORD_ATTRIBUTE_NAME, password);
            }
            return  Mono.just(contextAttributes);
        };
    }

spring.security.oauth2.client.provider.custom.token-uri=https://endpoint_to_get_token
spring.security.oauth2.client.registration.custom.client-id=<clientid>
spring.security.oauth2.client.registration.custom.client-secret=<client-secret>
spring.security.oauth2.client.registration.custom.client-authentication-method=post
spring.security.oauth2.client.registration.custom.authorization-grant-type=password
spring.security.oauth2.client.registration.custom.scope=AppIdClaimsTrust

注意：如https://github.com/jgrandja/spring-security-oauth-5-2-migrate/tree/master/client-app所述，我能够验证从web客户端调用Oauth受保护的endpoint

Answer 1

生成ReactiveOAuth2AuthorizedClientProvider时，不应使用authorizationCode。和刷新令牌不应用于计算机到计算机的通信。

最重要的是不要使用DefaultReactiveoAuth2AuthorizedClientManager。取而代之的是使用

AuthorizedClientServiceReactiveOAuth2AuthorizedClientManager authorizedClientManager =
        new AuthorizedClientServiceReactiveOAuth2AuthorizedClientManager(
            clientRegistrationRepository, authorizedClientService);
    authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);