content: /*
   * Default.java January 2010
   *
   * Copyright (C) 2010, 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;
  
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  
  /**
   * The <code>Default</code> annotation is used to specify that all
   * fields or methods should be serialized in a default manner. This
   * basically allows an objects fields or properties to be serialized
   * without the need to annotate them. This has advantages if the
   * format of the serialized object is not important, as it allows
   * the object to be serialized with a minimal use of annotations.
   * <pre>
   * 
   *    &#64;Root
   *    &#64;Default(DefaultType.FIELD)
   *    public class Example {
   *       ...
   *    }
   * 
   * </pre>
   * Defaults can be applied to either fields or property methods. If
   * this annotation is applied to a class, certain fields or methods
   * can be ignored using the <code>Transient</code> annotation. If a
   * member is marked as transient then it will not be serialized. The
   * defaults are applied only to those members that are not otherwise
   * annotated with an XML annotation.
   * 
   * @author Niall Gallagher
   * 
   * @see Transient
   */
  @Retention(RetentionPolicy.RUNTIME)
  public @interface Default {
     
     /**
      * This method is used to return the type of default that is to
      * be applied to the class. Defaults can be applied to either
      * fields or property methods. Any member with an XML annotation
      * will not be treated as a default. 
      * 
      * @return this returns the type of defaults to be applied
      */
     DefaultType value() default DefaultType.FIELD;
     
     /**
      * This is used to determine if the generated annotations are
      * required or not. By default generated parameters are required.
      * Setting this to false means that null values are accepted
      * by all defaulted fields or methods depending on the type.
      * 
      * @return this is used to determine if defaults are required
      */
     boolean required() default true;
  }