# Spring Authorization Server Advanced Patterns

## JPA Client Persistence

```java
@Entity
@Table(name = "oauth2_registered_client")
public class Client {
    @Id
    private String id;
    private String clientId;
    private String clientSecret;
    private String clientName;

    @Column(length = 1000)
    private String clientAuthenticationMethods;

    @Column(length = 1000)
    private String authorizationGrantTypes;

    @Column(length = 1000)
    private String redirectUris;

    @Column(length = 1000)
    private String scopes;

    @Column(length = 2000)
    private String clientSettings;

    @Column(length = 2000)
    private String tokenSettings;
}

@Repository
public interface ClientRepository extends JpaRepository<Client, String> {
    Optional<Client> findByClientId(String clientId);
}

@Component
@RequiredArgsConstructor
public class JpaRegisteredClientRepository implements RegisteredClientRepository {

    private final ClientRepository clientRepository;

    @Override
    public void save(RegisteredClient registeredClient) {
        clientRepository.save(toEntity(registeredClient));
    }

    @Override
    public RegisteredClient findById(String id) {
        return clientRepository.findById(id)
            .map(this::toRegisteredClient)
            .orElse(null);
    }

    @Override
    public RegisteredClient findByClientId(String clientId) {
        return clientRepository.findByClientId(clientId)
            .map(this::toRegisteredClient)
            .orElse(null);
    }

    // Conversion methods...
}
```

## JWT Configuration

```java
@Bean
public JWKSource<SecurityContext> jwkSource() {
    KeyPair keyPair = generateRsaKey();
    RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
    RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

    RSAKey rsaKey = new RSAKey.Builder(publicKey)
        .privateKey(privateKey)
        .keyID(UUID.randomUUID().toString())
        .build();

    JWKSet jwkSet = new JWKSet(rsaKey);
    return new ImmutableJWKSet<>(jwkSet);
}

private static KeyPair generateRsaKey() {
    try {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(2048);
        return keyPairGenerator.generateKeyPair();
    } catch (Exception ex) {
        throw new IllegalStateException(ex);
    }
}

@Bean
public AuthorizationServerSettings authorizationServerSettings() {
    return AuthorizationServerSettings.builder()
        .issuer("https://auth.example.com")
        .authorizationEndpoint("/oauth2/authorize")
        .tokenEndpoint("/oauth2/token")
        .jwkSetEndpoint("/oauth2/jwks")
        .tokenRevocationEndpoint("/oauth2/revoke")
        .tokenIntrospectionEndpoint("/oauth2/introspect")
        .oidcUserInfoEndpoint("/userinfo")
        .oidcLogoutEndpoint("/connect/logout")
        .build();
}
```

## Custom Token Claims

```java
@Bean
public OAuth2TokenCustomizer<JwtEncodingContext> jwtTokenCustomizer() {
    return context -> {
        if (context.getTokenType() == OAuth2TokenType.ACCESS_TOKEN) {
            Authentication principal = context.getPrincipal();

            Set<String> authorities = principal.getAuthorities().stream()
                .map(GrantedAuthority::getAuthority)
                .collect(Collectors.toSet());

            context.getClaims()
                .claim("authorities", authorities)
                .claim("email", getUserEmail(principal));
        }

        if (context.getTokenType().getValue().equals(OidcParameterNames.ID_TOKEN)) {
            context.getClaims()
                .claim("custom_claim", "custom_value");
        }
    };
}
```

## User Info Endpoint

```java
@Bean
public Function<OidcUserInfoAuthenticationContext, OidcUserInfo> userInfoMapper() {
    return context -> {
        OidcUserInfoAuthenticationToken authentication = context.getAuthentication();
        JwtAuthenticationToken principal = (JwtAuthenticationToken) authentication.getPrincipal();

        return OidcUserInfo.builder()
            .subject(principal.getName())
            .claim("email", principal.getToken().getClaim("email"))
            .claim("name", principal.getToken().getClaim("name"))
            .claim("roles", principal.getAuthorities().stream()
                .map(GrantedAuthority::getAuthority)
                .toList())
            .build();
    };
}
```

## Authorization Consent Controller

```java
@Controller
public class AuthorizationConsentController {

    private final RegisteredClientRepository registeredClientRepository;

    @GetMapping("/oauth2/consent")
    public String consent(Principal principal, Model model,
            @RequestParam(OAuth2ParameterNames.CLIENT_ID) String clientId,
            @RequestParam(OAuth2ParameterNames.SCOPE) String scope,
            @RequestParam(OAuth2ParameterNames.STATE) String state) {

        RegisteredClient client = registeredClientRepository.findByClientId(clientId);

        Set<String> requestedScopes = new HashSet<>(Arrays.asList(scope.split(" ")));

        model.addAttribute("clientId", clientId);
        model.addAttribute("clientName", client.getClientName());
        model.addAttribute("state", state);
        model.addAttribute("scopes", requestedScopes);
        model.addAttribute("principalName", principal.getName());

        return "consent";
    }
}
```

## Token Revocation

```java
@Service
@RequiredArgsConstructor
public class TokenRevocationService {

    private final OAuth2AuthorizationService authorizationService;

    public void revokeAllTokens(String principalName) {
        // Custom implementation to find and revoke all tokens for a user
    }
}

// REST endpoint for revocation (auto-configured)
// POST /oauth2/revoke
// token=<token>&token_type_hint=access_token
```

## Resource Server Integration

```java
@Configuration
@EnableWebSecurity
public class ResourceServerConfig {

    @Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
        http
            .authorizeHttpRequests(authorize -> authorize
                .requestMatchers("/public/**").permitAll()
                .requestMatchers("/api/**").hasAuthority("SCOPE_read")
                .anyRequest().authenticated()
            )
            .oauth2ResourceServer(oauth2 -> oauth2
                .jwt(jwt -> jwt
                    .jwtAuthenticationConverter(jwtAuthenticationConverter())
                )
            );
        return http.build();
    }

    @Bean
    public JwtAuthenticationConverter jwtAuthenticationConverter() {
        JwtGrantedAuthoritiesConverter authoritiesConverter = new JwtGrantedAuthoritiesConverter();
        authoritiesConverter.setAuthoritiesClaimName("authorities");
        authoritiesConverter.setAuthorityPrefix("");

        JwtAuthenticationConverter converter = new JwtAuthenticationConverter();
        converter.setJwtGrantedAuthoritiesConverter(authoritiesConverter);
        return converter;
    }
}
```

## Testing

```java
@SpringBootTest
@AutoConfigureMockMvc
class AuthorizationServerTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    void shouldReturnJwks() throws Exception {
        mockMvc.perform(get("/.well-known/openid-configuration"))
            .andExpect(status().isOk())
            .andExpect(jsonPath("$.issuer").value("http://localhost:9000"));
    }

    @Test
    void shouldRequireAuthentication() throws Exception {
        mockMvc.perform(get("/oauth2/authorize")
                .param("response_type", "code")
                .param("client_id", "web-client")
                .param("scope", "openid")
                .param("redirect_uri", "http://localhost:8080/callback"))
            .andExpect(status().is3xxRedirection())
            .andExpect(redirectedUrlPattern("**/login"));
    }

    @Test
    @WithMockUser
    void shouldIssueAuthorizationCode() throws Exception {
        // Test authorization code flow
    }
}
```
