content: /*
   * Instantiator.java April 2009
   *
   * Copyright (C) 2009, 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;
  
  /**
   * The <code>Instantiator</code> object is used to represent an single
   * constructor within an object. It contains the actual constructor
   * as well as the list of parameters. Each instantiator will score its
   * weight when given a <code>Criteria</code> object. This allows
   * the deserialization process to find the most suitable one to
   * use when instantiating an object.
   * 
   * @author Niall Gallagher
   */
  interface Creator {
  
     /**
      * This is used to instantiate the object using the default no
      * argument constructor. If for some reason the object can not be
      * instantiated then this will throw an exception with the reason.
      * 
      * @return this returns the object that has been instantiated
      */
     Object getInstance() throws Exception; 
     
     /**
      * This is used to instantiate the object using a constructor that
      * takes deserialized objects as arguments. The object that have
      * been deserialized can be taken from the <code>Criteria</code>
      * object which contains the deserialized values.
      *
      * @param criteria this contains the criteria to be used
      * 
      * @return this returns the object that has been instantiated
      */
     Object getInstance(Criteria criteria) throws Exception;
  
     /**
      * This is used to score this <code>Instantiator</code> object so that
      * it can be weighed amongst other constructors. The instantiator that
      * scores the highest is the one that is used for insIntantiation.
      * <p>
      * If any read only element or attribute is not a parameter in
      * the constructor then the constructor is discounted. This is
      * because there is no way to set the read only entity without a
      * constructor injection in to the instantiated object.
      * 
      * @param criteria this contains the criteria to be used
      * 
      * @return this returns the score based on the criteria provided
      */
     double getScore(Criteria criteria) throws Exception;
     
     /**
      * This is the signature associated with the creator. The signature
      * contains all the parameters associated with the creator as well
      * as the constructor that this represents. Exposing the signature
      * allows the creator to be validated.
      * 
      * @return this is the signature associated with the creator
      */
     Signature getSignature() throws Exception;
     
     /**
      * This is the type associated with the <code>Creator</code> object.
      * All instances returned from this creator will be of this type.
      * 
      * @return this returns the type associated with this creator
      */
     Class getType() throws Exception;
  }
  