content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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
   *
   *    http://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 org.apache.kafka.common.security.oauthbearer.internals.secured.assertion;
  
  import org.apache.kafka.common.security.oauthbearer.internals.secured.CachedFile;
  
  import java.io.File;
  import java.io.IOException;
  import java.security.GeneralSecurityException;
  
  import static org.apache.kafka.common.security.oauthbearer.internals.secured.CachedFile.RefreshPolicy.lastModifiedPolicy;
  import static org.apache.kafka.common.security.oauthbearer.internals.secured.CachedFile.STRING_JSON_VALIDATING_TRANSFORMER;
  
  /**
   * An {@link AssertionCreator} which takes a file from which the pre-created assertion is loaded and returned.
   * If the file changes on disk, it will be reloaded in memory without needing to restart the client/application.
   */
  public class FileAssertionCreator implements AssertionCreator {
  
      private final CachedFile<String> assertionFile;
  
      public FileAssertionCreator(File assertionFile) {
          this.assertionFile = new CachedFile<>(assertionFile, STRING_JSON_VALIDATING_TRANSFORMER, lastModifiedPolicy());
      }
  
      @Override
      public String create(AssertionJwtTemplate ignored) throws GeneralSecurityException, IOException {
          return assertionFile.transformed();
      }
  }
  