code: /*
   * SPDX-License-Identifier: Apache-2.0
   * Copyright 2018-2021 The Feast 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 feast.serving.service.config;
  
  import com.fasterxml.jackson.databind.DeserializationFeature;
  import com.fasterxml.jackson.databind.ObjectMapper;
  import com.fasterxml.jackson.databind.ObjectReader;
  import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
  import com.google.common.io.Resources;
  import com.google.inject.AbstractModule;
  import com.google.inject.Provides;
  import com.google.inject.Singleton;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  
  public class ApplicationPropertiesModule extends AbstractModule {
    private final String[] args;
  
    public ApplicationPropertiesModule(String[] args) {
      this.args = args;
    }
  
    @Provides
    @Singleton
    public ApplicationProperties provideApplicationProperties() throws IOException {
      ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
      mapper.findAndRegisterModules();
      mapper.setDefaultMergeable(Boolean.TRUE);
      mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
  
      ApplicationProperties properties = new ApplicationProperties();
      ObjectReader objectReader = mapper.readerForUpdating(properties);
  
      String[] filePaths = this.args[0].split(",");
      for (String filePath : filePaths) {
        objectReader.readValue(readPropertiesFile(filePath));
      }
  
      return properties;
    }
  
    /**
     * Read file path in spring compatible format, eg classpath:/application.yml or
     * file:/path/application.yml
     */
    private byte[] readPropertiesFile(String filePath) throws IOException {
      if (filePath.startsWith("classpath:")) {
        filePath = filePath.substring("classpath:".length());
        if (filePath.startsWith("/")) {
          filePath = filePath.substring(1);
        }
  
        return Resources.toByteArray(Resources.getResource(filePath));
      }
  
      if (filePath.startsWith("file")) {
        filePath = filePath.substring("file:".length());
      }
  
      return Files.readAllBytes(Path.of(filePath));
    }
  }
  