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 com.aliyun.oss.common.utils;
  
  import static com.aliyun.oss.common.utils.LogUtils.logException;
  
  import java.io.InputStream;
  import java.util.Properties;
  
  public class VersionInfoUtils {
  
      private static final String VERSION_INFO_FILE = "versioninfo.properties";
      private static final String USER_AGENT_PREFIX = "aliyun-sdk-java";
  
      private static String version = null;
  
      private static String defaultUserAgent = null;
  
      public static String getVersion() {
          if (version == null) {
              initializeVersion();
          }
          return version;
      }
  
      public static String getDefaultUserAgent() {
          if (defaultUserAgent == null) {
              defaultUserAgent = USER_AGENT_PREFIX + "/" + getVersion() + "(" + System.getProperty("os.name") + "/"
                      + System.getProperty("os.version") + "/" + System.getProperty("os.arch") + ";"
                      + System.getProperty("java.version") + ")";
          }
          return defaultUserAgent;
      }
  
      private static void initializeVersion() {
          InputStream inputStream = VersionInfoUtils.class.getClassLoader().getResourceAsStream(VERSION_INFO_FILE);
          Properties versionInfoProperties = new Properties();
          try {
              if (inputStream == null) {
                  throw new IllegalArgumentException(VERSION_INFO_FILE + " not found on classpath");
              }
  
              versionInfoProperties.load(inputStream);
              version = versionInfoProperties.getProperty("version");
          } catch (Exception e) {
              logException("Unable to load version information for the running SDK: ", e);
              version = "unknown-version";
          }
      }
  }
  