content: /*
   * CharacterArrayTransform.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.lang.reflect.Array;
  
  /**
   * The <code>CharacterArrayTransform</code> is used to transform text
   * 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 char[] text;
   *    
   * </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 CharacterArrayTransform implements Transform {     
  
     /**
      * This is the entry type for the primitive array to be created.
      */
     private final Class entry;
  
     /**
      * Constructor for the <code>PrimitiveArrayTransform</code> object.
      * This is used to create a transform that will create primitive
      * arrays and populate the values of the array with values from a
      * comma separated list of individual values for the entry type.
      * 
      * @param entry this is the entry component type for the array
      */
     public CharacterArrayTransform(Class entry) {
        this.entry = entry;
     }       
     
     /**
      * 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 value this is the string representation of the value
      * 
      * @return this returns an appropriate instanced to be used
      */
     public Object read(String value) throws Exception {
        char[] list = value.toCharArray();      
        int length = list.length;
  
        if(entry == char.class) {
           return list;
        }
        return read(list, length);
     }
     
     /**
      * 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 list this is the string representation of the value
      * @param length this is the number of string values to use
      * 
      * @return this returns an appropriate instanced to be used
      */
     private Object read(char[] list, int length) throws Exception {
        Object array = Array.newInstance(entry, length);
  
        for(int i = 0; i < length; i++) {
           Array.set(array, i, list[i]);                
        }
        return array;
     }
     
     /**
      * 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 value this is the value to be converted to a string
      * 
      * @return this is the string representation of the given value
      */
     public String write(Object value) throws Exception {
        int length = Array.getLength(value);
  
        if(entry == char.class) {
           char[] array = (char[])value;
           return new String(array);
        }
        return write(value, length);      
     }
     
     /**
      * 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 value this is the value to be converted to a string
      * 
      * @return this is the string representation of the given value
      */
     private String write(Object value, int length) throws Exception {
        StringBuilder text = new StringBuilder(length);
  
        for(int i = 0; i < length; i++) {
           Object entry = Array.get(value, i);         
  
           if(entry != null) {
              text.append(entry);                             
           }         
        }      
        return text.toString();
     }
  }
  