content: /*
   * LocaleTransform.java May 2007
   *
   * Copyright (C) 2007, 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.transform;
  
  import java.util.regex.Pattern;
  import java.util.Locale;
  
  /**
   * The <code>LocaleTransform</code> is used to transform locale
   * values to and from string representations, which will be inserted
   * in the generated XML document as the value place holder. The
   * value must be readable and writable in the same format. Fields
   * and methods annotated with the XML attribute annotation will use
   * this to persist and retrieve the value to and from the XML source.
   * <pre>
   * 
   *    &#64;Attribute
   *    private Locale locale;
   *    
   * </pre>
   * As well as the XML attribute values using transforms, fields and
   * methods annotated with the XML element annotation will use this.
   * Aside from the obvious difference, the element annotation has an
   * advantage over the attribute annotation in that it can maintain
   * any references using the <code>CycleStrategy</code> object. 
   * 
   * @author Niall Gallagher
   */
  class LocaleTransform implements Transform<Locale>{
  
     /**
      * This is the pattern used to split the parts of the locale.
      */
     private final Pattern pattern;
     
     /**
      * Constructor for the <code>LocaleTransform</code> object. This
      * is used to create a transform that will convert locales to and
      * from string representations. The representations use the Java
      * locale representation of language, country, and varient.
      */
     public LocaleTransform() {
        this.pattern = Pattern.compile("_");
     }
     
     /**
      * This method is used to convert the string value given to an
      * appropriate representation. This is used when an object is
      * being deserialized from the XML document and the value for
      * the string representation is required.
      * 
      * @param locale the string representation of the date value 
      * 
      * @return this returns an appropriate instanced to be used
      */
     public Locale read(String locale) throws Exception {
        String[] list = pattern.split(locale);
        
        if(list.length < 1) {
           throw new InvalidFormatException("Invalid locale %s", locale);
        }
        return read(list);
     }
     
     /**
      * This method is used to convert the string value given to an
      * appropriate representation. This is used when an object is
      * being deserialized from the XML document and the value for
      * the string representation is required.
      * 
      * @param locale the string representation of the date value 
      * 
      * @return this returns an appropriate instanced to be used
      */
     private Locale read(String[] locale)  throws Exception {
        String[] list = new String[] {"", "", ""};
        
        for(int i = 0; i < list.length; i++) {
           if(i < locale.length) {         
              list[i] = locale[i];
           }
        }
        return new Locale(list[0], list[1], list[2]);
     }
     
     /**
      * This method is used to convert the provided value into an XML
      * usable format. This is used in the serialization process when
      * there is a need to convert a field value in to a string so 
      * that that value can be written as a valid XML entity.
      * 
      * @param locale this is the value to be converted to a string
      * 
      * @return this is the string representation of the given date
      */
     public String write(Locale locale) {
        return locale.toString();
     }
  }