StreamsConfigurator.java

/*
 * 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
 *
 *   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.streams.config;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.typesafe.config.Config;
import com.typesafe.config.ConfigFactory;
import com.typesafe.config.ConfigRenderOptions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.net.MalformedURLException;
import java.net.URL;

/**
 * StreamsConfigurator supplies the entire typesafe tree to runtimes and modules.
 *
 * StreamsConfigurator also supplies StreamsConfiguration POJO to runtimes and modules.
 *
 */
public class StreamsConfigurator {

  private static final Logger LOGGER = LoggerFactory.getLogger(ComponentConfigurator.class);

  private static final ObjectMapper mapper = new ObjectMapper();

  /*
      Pull all configuration files from the classpath, system properties, and environment variables
   */
  public static Config config = ConfigFactory.load();

  public static Config getConfig() {
    return config;
  }

  public static Config resolveConfig(String configUrl) throws MalformedURLException {
    URL url = new URL(configUrl);
    Config urlConfig = ConfigFactory.parseURL(url);
    urlConfig.resolve();
    config = urlConfig;
    return config;
  }



  public static StreamsConfiguration detectConfiguration() {
    return detectConfiguration(config);
  }

  public static StreamsConfiguration detectConfiguration(Config typesafeConfig) {

    StreamsConfiguration pojoConfig = null;

    try {
      pojoConfig = mapper.readValue(typesafeConfig.root().render(ConfigRenderOptions.concise()), StreamsConfiguration.class);
    } catch (Exception e) {
      e.printStackTrace();
      LOGGER.warn("Could not parse:", typesafeConfig);
    }

    return pojoConfig;
  }

  public static StreamsConfiguration mergeConfigurations(Config base, Config delta) {

    Config merged = delta.withFallback(base);

    StreamsConfiguration pojoConfig = null;

    try {
      pojoConfig = mapper.readValue(merged.root().render(ConfigRenderOptions.concise()), StreamsConfiguration.class);
    } catch (Exception e) {
      e.printStackTrace();
      LOGGER.warn("Failed to merge.");
    }

    return pojoConfig;
  }
}