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 org.apache.aries.blueprint.di;
  
  import java.lang.reflect.Type;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.LinkedHashSet;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Queue;
  import java.util.Set;
  import java.util.SortedSet;
  import java.util.TreeSet;
  
  import org.apache.aries.blueprint.utils.ReflectionUtils;
  import org.osgi.service.blueprint.container.ComponentDefinitionException;
  import org.osgi.service.blueprint.container.ReifiedType;
  
  /**
   * @version $Rev$ $Date$
   */
  public class CollectionRecipe extends AbstractRecipe {
  
      private final List<Recipe> list;
      private final Class<?> collectionTypeClass;
      private final String defaultValueType;
  
      public CollectionRecipe(String name, Class<?> collectionType, String valueType) {
          super(name);
          if (collectionType == null) throw new NullPointerException("type is null");
          this.collectionTypeClass = collectionType;
          this.defaultValueType = (valueType != null) ? valueType : Object.class.getName();
          this.list = new ArrayList<Recipe>();
      }
  
      public List<Recipe> getDependencies() {
          List<Recipe> nestedRecipes = new ArrayList<Recipe>(list.size());
          for (Recipe recipe : list) {
              if (recipe != null) {
                  nestedRecipes.add(recipe);
              }
          }
          return nestedRecipes;
      }
  
      protected Object internalCreate() throws ComponentDefinitionException {
          Class type = getCollection(collectionTypeClass);
  
          if (!ReflectionUtils.hasDefaultConstructor(type)) {
              throw new ComponentDefinitionException("Type does not have a default constructor " + type.getName());
          }
  
          // create collection instance
          Object o;
          try {
              o = type.newInstance();
          } catch (Exception e) {
              throw new ComponentDefinitionException("Error while creating collection instance: " + type.getName());
          }
          if (!(o instanceof Collection)) {
              throw new ComponentDefinitionException("Specified collection type does not implement the Collection interface: " + type.getName());
          }
          Collection instance = (Collection) o;
  
          ReifiedType defaultConversionType = loadType(defaultValueType);
          Type conversionType = null;
          for (Recipe recipe : list) {
              Object value;
              if (recipe != null) {
                  try {
                      conversionType = defaultConversionType.getRawClass();
                      if (recipe instanceof ValueRecipe) {
                          conversionType = ((ValueRecipe) recipe).getValueType();
                      }
                      value = convert(recipe.create(), conversionType);
                  } catch (Exception e) {
                      throw new ComponentDefinitionException("Unable to convert value " + recipe + " to type " + conversionType, e);
                  }
              } else {
                  value = null;
              }
              instance.add(value);
          }
          return instance;
      }
  
      public void add(Recipe value) {
          list.add(value);
      }
  
      public static Class getCollection(Class type) {
          if (ReflectionUtils.hasDefaultConstructor(type)) {
              return type;
          } else if (SortedSet.class.isAssignableFrom(type)) {
              return TreeSet.class;
          } else if (Set.class.isAssignableFrom(type)) {
              return LinkedHashSet.class;
          } else if (List.class.isAssignableFrom(type)) {
              return ArrayList.class;
          } else if (Queue.class.isAssignableFrom(type)) {
              return LinkedList.class;
          } else {
              return ArrayList.class;
          }
      }
  }
  