/*

  * 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.giraph.utils;

 import org.apache.log4j.Logger;

 import com.google.common.collect.Maps;

 import com.google.common.io.Resources;

 import java.io.IOException;

 import java.net.URL;

 import java.util.Map;

 import java.util.Properties;

 /**

  * Versions of Giraph dependencies. This pulls version information from a known

  * properties file. That file is created by maven when building the jar and

  * populated with versions from the pom. We put the properties file in a known

  * resources folder so that it is easy to pick up.

  *

  * See http://bit.ly/19LQyrK for more information.

  */

 public class GiraphDepVersions {

   /** Logger */

   private static final Logger LOG = Logger.getLogger(GiraphDepVersions.class);

   /** Path to resource */

   private static final String RESOURCE_NAME =

       "org/apache/giraph/versions.properties";

   /** Singleton */

   private static final GiraphDepVersions INSTANCE = new GiraphDepVersions();

   /** The properties read */

   private final Properties properties;

   /** Constructor */

   private GiraphDepVersions() {

     URL url = Resources.getResource(RESOURCE_NAME);

     properties = new Properties();

     try {

       properties.load(url.openStream());

     } catch (IOException e) {

       LOG.error("Could not read giraph versions from file " + RESOURCE_NAME);

     }

   }

   /**

    * Get singleton instance

    *

    * @return singleton

    */

   public static GiraphDepVersions get() {

     return INSTANCE;

   }

   public Properties getProperties() {

     return properties;

   }

   /**

    * Get version of the named dependency, or null if not found

    *

    * @param name dependency name

    * @return version, or null

    */

   public String versionOf(String name) {

     return properties.getProperty(name);

   }

   /** Log the dependency versions we're using */

   public void logVersionsUsed() {

     Map<String, String> sortedVersions = Maps.newTreeMap();

     for (Map.Entry<Object, Object> entry : properties.entrySet()) {

       sortedVersions.put(entry.getKey().toString(),

           entry.getValue().toString());

     }

     StringBuilder sb = new StringBuilder(sortedVersions.size() * 20);

     for (Map.Entry<String, String> entry : sortedVersions.entrySet()) {

       sb.append("  ").append(entry.getKey()).append(": ").

           append(entry.getValue()).append("\n");

     }

     LOG.info("Versions of Giraph dependencies =>\n" + sb);

   }

 }