问题描述： 在使用Angular和Spring Boot集成Keycloak时，当尝试访问受保护的资源时，遇到了401错误。

解决方法： 以下是可能的解决方法，包含了关键代码示例：

1. 确保Keycloak服务器已正确配置，并且已在Angular和Spring Boot应用程序中进行了正确的集成。

2. 在Angular应用程序的身份验证服务中设置Bearer令牌：

import { Injectable } from '@angular/core';
import { KeycloakService } from 'keycloak-angular';

@Injectable()
export class AuthService {

  constructor(private keycloakService: KeycloakService) { }

  getToken(): Promise {
    return new Promise(async (resolve, reject) => {
      try {
        const keycloak = await this.keycloakService.getKeycloakInstance();
        if (keycloak.token) {
          resolve(keycloak.token);
        } else {
          reject('No token found');
        }
      } catch (error) {
        reject(error);
      }
    });
  }

}

3. 在Angular拦截器中添加Bearer令牌：

import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpRequest, HttpHandler, HttpEvent } from '@angular/common/http';
import { Observable } from 'rxjs';
import { KeycloakService } from 'keycloak-angular';

@Injectable()
export class AuthInterceptor implements HttpInterceptor {

  constructor(private keycloakService: KeycloakService) { }

  intercept(request: HttpRequest, next: HttpHandler): Observable> {
    return new Observable((observer) => {
      this.keycloakService.getToken()
        .then((token) => {
          const headers = request.headers
            .set('Authorization', `Bearer ${token}`);
          const authRequest = request.clone({ headers });
          observer.next(authRequest);
          observer.complete();
        })
        .catch((error) => {
          observer.error(error);
        });
    });
  }

}

4. 在Spring Boot应用程序的WebSecurity配置中添加Keycloak验证：

@Configuration
@EnableWebSecurity
public class SecurityConfig extends KeycloakWebSecurityConfigurerAdapter {

  @Autowired
  public void configureGlobal(AuthenticationManagerBuilder auth) {
    KeycloakAuthenticationProvider keycloakProvider = keycloakAuthenticationProvider();
    keycloakProvider.setGrantedAuthoritiesMapper(new SimpleAuthorityMapper());
    auth.authenticationProvider(keycloakProvider);
  }

  @Bean
  public KeycloakConfigResolver keycloakConfigResolver() {
    return new KeycloakSpringBootConfigResolver();
  }

  @Override
  protected void configure(HttpSecurity http) throws Exception {
    super.configure(http);
    http.authorizeRequests()
      .antMatchers("/api/**").authenticated()
      .anyRequest().permitAll();
  }

}

5. 在Spring Boot应用程序的应用配置文件中添加Keycloak配置：

# Keycloak Configuration
keycloak.realm=
keycloak.auth-server-url=
keycloak.ssl-required=external
keycloak.resource=
keycloak.credentials.secret=
keycloak.use-resource-role-mappings=true
keycloak.bearer-only=true

以上是一种解决方法，可以根据实际情况进行调整和修改。