content: /*
   * ParameterMap.java May 2012
   *
   * Copyright (C) 2012, Niall Gallagher <niallg@users.sf.net>
   *
   * Licensed 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.odps.simpleframework.xml.core;
  
  import static java.util.Collections.emptyList;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  import java.util.List;
  
  /**
   * The <code>ParameterMap</code> object represents of parameters
   * that are present within an objects constructors. This is used
   * for convenience to iterate over parameters and also to acquire
   * parameters by index, that is, the position they appear in the
   * constructor signature.
   * 
   * @author Niall Gallagher
   */
  class ParameterMap extends LinkedHashMap<Object, Parameter> implements Iterable<Parameter>{
  
     /**
      * Constructor for the <code>ParameterMap</code> object. This 
      * is used to create a linked hash map of parameters where each
      * parameter can be acquired by its index within a constructor.
      */
     public ParameterMap() {
        super();
     }
     
     /**
      * This is used to iterate over <code>Parameter</code> objects.
      * Parameters are iterated in the order that they are added to
      * the map. This is primarily used for convenience iteration. 
      * 
      * @return this returns an iterator for the parameters
      */
     public Iterator<Parameter> iterator() {
        return values().iterator();
     }
     
     /**
      * This is used to acquire a <code>Parameter</code> using the
      * position of that parameter within the constructors. This 
      * allows a builder to determine which parameters to use.
      * 
      * @param ordinal this is the position of the parameter
      * 
      * @return this returns the parameter for the position
      */
     public Parameter get(int ordinal) {
        return getAll().get(ordinal);
     }
     
     /**
      * This is used to acquire an list of <code>Parameter</code>
      * objects in declaration order. This list will help with the
      * resolution of the correct constructor for deserialization
      * of the XML. It also provides a faster method of iteration.
      * 
      * @return this returns the parameters in declaration order
      */
     public List<Parameter> getAll() {
        Collection<Parameter> list = values();
        
        if(!list.isEmpty()) {
           return new ArrayList(list);
        }
        return emptyList();
     }
  }
  