Pivot Resource Server Sample

Changed sample to manage its own JwtDecoder, allowing the Nimbus
Jwt Decoder Builder API to evolve during milestone development.

samples/boot/oauth2resourceserver/src/main/java/sample/OAuth2ResourceServerSecurityConfiguration.java

@@ -15,12 +15,15 @@
  */
 package sample;
 
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.http.HttpMethod;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
-import org.springframework.http.HttpMethod;
-
-import static org.springframework.security.config.Customizer.withDefaults;
+import org.springframework.security.config.annotation.web.configurers.oauth2.server.resource.OAuth2ResourceServerConfigurer;
+import org.springframework.security.oauth2.jwt.JwtDecoder;
+import org.springframework.security.oauth2.jwt.NimbusJwtDecoder;
 
 /**
  * @author Josh Cummings
@@ -28,6 +31,8 @@ import static org.springframework.security.config.Customizer.withDefaults;
 @EnableWebSecurity
 public class OAuth2ResourceServerSecurityConfiguration extends WebSecurityConfigurerAdapter {
 
+	@Value("${spring.security.oauth2.resourceserver.jwt.jwk-set-uri}") String jwkSetUri;
+
 	@Override
 	protected void configure(HttpSecurity http) throws Exception {
 		// @formatter:off
@@ -38,10 +43,12 @@ public class OAuth2ResourceServerSecurityConfiguration extends WebSecurityConfig
 					.antMatchers(HttpMethod.POST, "/message/**").hasAuthority("SCOPE_message:write")
 					.anyRequest().authenticated()
 			)
-			.oauth2ResourceServer(oauth2ResourceServer ->
-				oauth2ResourceServer
-					.jwt(withDefaults())
-			);
+			.oauth2ResourceServer(OAuth2ResourceServerConfigurer::jwt);
 		// @formatter:on
 	}
+
+	@Bean
+	JwtDecoder jwtDecoder() {
+		return NimbusJwtDecoder.withJwkSetUri(this.jwkSetUri).build();
+	}
 }