Add Token Exchange grant to demo-client sample

Issue gh-60

samples/users-resource/src/main/java/sample/config/SecurityConfig.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2020-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package sample.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.Customizer;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.web.SecurityFilterChain;
+
+/**
+ * @author Steve Riesenberg
+ * @since 1.3
+ */
+@Configuration
+@EnableWebSecurity
+public class SecurityConfig {
+
+	@Bean
+	public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
+		// @formatter:off
+		http
+			.securityMatcher("/user/**")
+			.authorizeHttpRequests((authorize) -> authorize
+				.requestMatchers("/user/**").hasAuthority("SCOPE_user.read")
+			)
+			.oauth2ResourceServer((oauth2ResourceServer) -> oauth2ResourceServer
+				.jwt(Customizer.withDefaults())
+			)
+			.oauth2Client(Customizer.withDefaults());
+		// @formatter:on
+
+		return http.build();
+	}
+
+}