DaoRegisteredClientRepository for Spring Authorization Server

DaoRegisteredClientRepository.java

/*
 * Copyright 2020-2021 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.
 */

import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.security.oauth2.server.authorization.client.RegisteredClient;
import org.springframework.security.oauth2.server.authorization.client.RegisteredClientRepository;

/**
 * @author Steve Riesenberg
 */
public final class DaoRegisteredClientRepository implements RegisteredClientRepository {
	private final RegisteredClient registeredClient;
	private final UserDetailsService userDetailsService;

	public DaoRegisteredClientRepository(RegisteredClient registeredClient, UserDetailsService userDetailsService) {
		this.registeredClient = registeredClient;
		this.userDetailsService = userDetailsService;
	}

	@Override
	public void save(RegisteredClient registeredClient) {
		throw new UnsupportedOperationException();
	}

	@Override
	public RegisteredClient findById(String id) {
		return this.registeredClient.getId().equals(id) ? this.registeredClient : null;
	}

	@Override
	public RegisteredClient findByClientId(String clientId) {
		UserDetails userDetails;
		try {
			userDetails = this.userDetailsService.loadUserByUsername(clientId);
		} catch (UsernameNotFoundException ignored) {
			return null;
		}

		return RegisteredClient.from(this.registeredClient)
				.clientId(userDetails.getUsername())
				.clientSecret(userDetails.getPassword())
				.build();
	}
}