content: /**
   * Copyright 2007 The Apache Software Foundation
   *
   * 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.alibaba.wasp.conf;
  
  import com.alibaba.wasp.util.VersionInfo;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.HBaseConfiguration;
  
  import java.util.Map.Entry;
  
  /**
   * Adds Wasp configuration files to a Configuration
   */
  public class WaspConfiguration extends Configuration {
  
    private static void checkDefaultsVersion(Configuration conf) {
      if (conf.getBoolean("wasp.defaults.for.version.skip", Boolean.TRUE)) return;
      String defaultsVersion = conf.get("wasp.defaults.for.version");
      String thisVersion = VersionInfo.getVersion();
      if (!thisVersion.equals(defaultsVersion)) {
        throw new RuntimeException(
          "wasp-default.xml file seems to be for and old version of Wasp (" +
          defaultsVersion + "), this version is " + thisVersion);
      }
    }
  
    public static Configuration addWaspResources(Configuration conf) {
      conf.addResource("wasp-default.xml");
      conf.addResource("wasp-site.xml");
  
      checkDefaultsVersion(conf);
      return conf;
    }
  
    /**
     * Creates a Configuration with HBase and Wasp resources
     * 
     * @return a Configuration with HBase and Wasp resources
     */
    public static Configuration create() {
      Configuration conf = HBaseConfiguration.create();
      return addWaspResources(conf);
    }
  
    /**
     * Creates a clone of passed configuration.
     * @param that Configuration to clone.
     * @return a clone of passed configuration.
     */
    public static Configuration create(final Configuration that) {
      Configuration conf = create();
      merge(conf, that);
      return conf;
    }
  
    /**
     * Merge two configurations.
     * @param destConf the configuration that will be overwritten with items
     *                 from the srcConf
     * @param srcConf the source configuration
     **/
    public static void merge(Configuration destConf, Configuration srcConf) {
      for (Entry<String, String> e : srcConf) {
        destConf.set(e.getKey(), e.getValue());
      }
    }
    
    /**
     * 
     * @return whether to show Wasp Configuration in servlet
     */
    public static boolean isShowConfInServlet() {
      boolean isShowConf = false;
      try {
        if (Class.forName("org.apache.hadoop.conf.ConfServlet") != null) {
          isShowConf = true;  
        }
      } catch (Exception e) {
        
      }
      return isShowConf;
    }
  }