content: package org.apache.archiva.repository.content.base;
  
  /*
   * 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.
   */
  
  import org.apache.archiva.repository.ManagedRepositoryContent;
  import org.apache.archiva.repository.content.base.builder.OptBuilder;
  import org.apache.archiva.repository.content.base.builder.WithAssetBuilder;
  import org.apache.archiva.repository.content.base.builder.WithRepositoryBuilder;
  import org.apache.archiva.repository.storage.StorageAsset;
  import org.apache.commons.lang3.StringUtils;
  
  /**
   * Builder for content item. Must be extended by subclasses.
   * The builder uses chained interfaces for building the required attributes. That means you have to set
   * some certain attributes, before you can build the content item instance via the {@link #build()} method.
   * <p>
   * Subclasses should extend from this class and provide the interface/class for the destination item,
   * a interface for the optional attributes and a interface that is returned after the last required attribute is
   * set.
   * <p>
   * The interface for optional attributes should inherit from {@link OptBuilder}
   *
   * @param <I> the item class that should be built
   * @param <O> the class/interface for the optional attributes
   * @param <N> the class/interface for the next (required) attribute after the base attributes are set
   */
  abstract class ContentItemBuilder<I extends BaseContentItem, O extends OptBuilder<I, O>, N>
      implements WithRepositoryBuilder, WithAssetBuilder<N>,
      OptBuilder<I, O>
  {
  
      protected I item;
  
      protected ContentItemBuilder( I item )
      {
          this.item = item;
      }
  
      protected abstract O getOptBuilder( );
  
      protected abstract N getNextBuilder( );
  
      @Override
      public WithAssetBuilder<N> withRepository( ManagedRepositoryContent repository )
      {
          if ( repository == null )
          {
              throw new IllegalArgumentException( "Repository may not be null" );
          }
          ( (BaseContentItem) item ).repository = repository;
          return this;
      }
  
      @Override
      public N withAsset( StorageAsset asset )
      {
          if ( asset == null )
          {
              throw new IllegalArgumentException( "Asset may not be null" );
          }
          ( (BaseContentItem) item ).asset = asset;
          return getNextBuilder( );
      }
  
      @Override
      public O withAttribute( String key, String value )
      {
          if ( StringUtils.isEmpty( key ) )
          {
              throw new IllegalArgumentException( "Attribute key may not be null" );
          }
          item.putAttribute( key, value );
          return getOptBuilder( );
      }
  
      protected void setRepository( ManagedRepositoryContent repository )
      {
          item.repository = repository;
      }
  
      @Override
      public I build( )
      {
          return item;
      }
  
  }
  