    001/*
    002 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
    003 *
    004 * Project and contact information: http://www.cascading.org/
    005 *
    006 * This file is part of the Cascading project.
    007 *
    008 * Licensed under the Apache License, Version 2.0 (the "License");
    009 * you may not use this file except in compliance with the License.
    010 * You may obtain a copy of the License at
    011 *
    012 *     http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing, software
    015 * distributed under the License is distributed on an "AS IS" BASIS,
    016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    017 * See the License for the specific language governing permissions and
    018 * limitations under the License.
    019 */
    020
    021package cascading.flow.hadoop;
    022
    023import cascading.property.ConfigDef;
    024import org.apache.hadoop.conf.Configuration;
    025
    026/**
    027*
    028*/
    029public class ConfigurationSetter implements ConfigDef.Setter
    030  {
    031  private final Configuration conf;
    032
    033  public ConfigurationSetter( Configuration conf )
    034    {
    035    this.conf = conf;
    036    }
    037
    038  @Override
    039  public String set( String key, String value )
    040    {
    041    String oldValue = get( key );
    042
    043    conf.set( key, value );
    044
    045    return oldValue;
    046    }
    047
    048  @Override
    049  public String update( String key, String value )
    050    {
    051    String oldValue = get( key );
    052
    053    if( oldValue == null )
    054      conf.set( key, value );
    055    else if( !oldValue.contains( value ) )
    056      conf.set( key, oldValue + "," + value );
    057
    058    return oldValue;
    059    }
    060
    061  @Override
    062  public String get( String key )
    063    {
    064    String value = conf.get( key );
    065
    066    if( value == null || value.isEmpty() )
    067      return null;
    068
    069    return value;
    070    }
    071  }