<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>3.4.4</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-security</artifactId>
		</dependency>
		<!-- jwt token相關依賴-->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-oauth2-resource-server</artifactId>
		</dependency>
	<dependencies>

@Configuration
@EnableWebSecurity
public class SecurityConfig {
  @Value("${jwt.public.key}")
  RSAPublicKey key;
  @Value("${jwt.private.key}")
  RSAPrivateKey priv;
  @Bean
  public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
    // @formatter:off
    http
        .authorizeHttpRequests((authorize) -> authorize
            .anyRequest().authenticated()
        )
        .csrf((csrf) -> csrf.ignoringRequestMatchers("/token"))
        .httpBasic(Customizer.withDefaults())
        .oauth2ResourceServer(OAuth2ResourceServerConfigurer::jwt)
        .sessionManagement((session) -> session.sessionCreationPolicy(SessionCreationPolicy.STATELESS))
        .exceptionHandling((exceptions) -> exceptions
            .authenticationEntryPoint(new BearerTokenAuthenticationEntryPoint())
            .accessDeniedHandler(new BearerTokenAccessDeniedHandler())
        );
    // @formatter:on
    return http.build();
  }
  @Bean
  UserDetailsService users() {
    // @formatter:off
    return new InMemoryUserDetailsManager(
        User.withUsername("user")
            .password("{noop}password")
            .authorities("app")
            .build()
    );
    // @formatter:on
  }
  @Bean
  JwtDecoder jwtDecoder() {
    return NimbusJwtDecoder.withPublicKey(this.key).build();
  }
  @Bean
  JwtEncoder jwtEncoder() {
    JWK jwk = new RSAKey.Builder(this.key).privateKey(this.priv).build();
    JWKSource<SecurityContext> jwks = new ImmutableJWKSet<>(new JWKSet(jwk));
    return new NimbusJwtEncoder(jwks);
  }
}

public interface UserDetailsService {
	/**
	 * Locates the user based on the username. In the actual implementation, the search
	 * may possibly be case sensitive, or case insensitive depending on how the
	 * implementation instance is configured. In this case, the <code>UserDetails</code>
	 * object that comes back may have a username that is of a different case than what
	 * was actually requested..
	 * @param username the username identifying the user whose data is required.
	 * @return a fully populated user record (never <code>null</code>)
	 * @throws UsernameNotFoundException if the user could not be found or the user has no
	 * GrantedAuthority
	 */
	UserDetails loadUserByUsername(String username) throws UsernameNotFoundException;
}

  @Bean
  PasswordEncoder passwordEncoder(){
    return new BCryptPasswordEncoder();
  }

@RestController
public class TokenController {
  @Autowired
  JwtEncoder encoder;
  @PostMapping("/token")
  public String token(Authentication authentication) {
    Instant now = Instant.now();
    long expiry = 36000L;
    // @formatter:off
    String scope = authentication.getAuthorities().stream()
        .map(GrantedAuthority::getAuthority)
        .collect(Collectors.joining(" "));
    JwtClaimsSet claims = JwtClaimsSet.builder()
        .issuer("self")
        .issuedAt(now)
        .expiresAt(now.plusSeconds(expiry))
        .subject(authentication.getName())
        .claim("scope", scope)
        .build();
    // @formatter:on
    return this.encoder.encode(JwtEncoderParameters.from(claims)).getTokenValue();
  }
}

curl -XPOST user:password@localhost:8080/token

eyJhbGciOiJSUzI1NiJ9.eyJpc3MiOiJzZWxmIiwic3ViIjoidXNlciIsImV4cCI6MTYwNDA0MzA1MSwiaWF0IjoxNjA0MDA3MDUxfQ.yDF_JgSwl5sk21CF7AE1AYbYzRd5YYqe3MIgSWpgN0t2UqsjaaEDhmmICKizt-_0iZy8nkEpNnvgqv5bOHDhs7AXlYS1pg8dgPKuyfkhyVIKa3DhuGyb7tFjwJxHpr128BXf1Dbq-p7Njy46tbKsZhP5zGTjdXlqlAhR4Bl5Fxaxr7D0gdTVBVTlUp9DCy6l-pTBpsvHxShkjXJ0GHVpIZdB-c2e_K9PfTW5MDPcHekG9djnWPSEy-fRvKzTsyVFhdy-X3NXQWWkjFv9bNarV-bhxMlzqhujuaeXJGEqUZlkhBxTsqFr1N7XVcmhs3ECdjEyun2fUSge4BoC7budsQ

export TOKEN=`curl -XPOST user:password@localhost:8080/token`

curl -H "Authorization: Bearer $TOKEN" localhost:8080 && echo

Hello, user!

  @PreAuthorize("hasAuthority('SCOPE_ADMIN')")//JWT token解析后會加一個前綴'scope'
  @GetMapping("/admin")
  public String admin(Authentication authentication){
    return authentication.getAuthorities().toString();
  }