package org.apache.ojb.broker.accesslayer.conversions;

 /* Copyright 2004-2005 The Apache Software Foundation

  *

  * 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.

  */

 import java.util.ArrayList;

 import java.util.List;

 import org.apache.commons.lang.StringUtils;

 /**

  * This implementation of the {@link FieldConversion} interface converts

  * between a {@link java.util.List} of {@link java.lang.String} objects and a database

  * <em>varchar</em> field.

  * <br/>

  * Strings may not contain "#" as this is used as separator.

  *

  * @author Guillaume Nodet

  * @version $Id: StringList2VarcharFieldConversion.java,v 1.1 2007-08-24 22:17:31 ewestfal Exp $

  */

 public class StringList2VarcharFieldConversion implements FieldConversion

 {

     private static final String NULLVALUE = "#NULL#";

     private static final String EMPTYCOLLEC = "#EMTPY#";

     public StringList2VarcharFieldConversion()

     {

     }

     /* (non-Javadoc)

      * @see org.apache.ojb.broker.accesslayer.conversions.FieldConversion#javaToSql(java.lang.Object)

      */

     public Object javaToSql(Object source) throws ConversionException

     {

         if (source == null)

         {

             return NULLVALUE;

         }

         try

         {

             List stringList = (List) source;

             if (stringList.isEmpty())

             {

                 return NULLVALUE;

             }

             StringBuffer result = new StringBuffer();

             for (int i = 0; i < stringList.size(); i++)

             {

                 String newSt = (String) stringList.get(i);

                 // introduced in JDK 1.4, replace with commons-lang

                 // newSt = newSt.replaceAll("#", "##");

                 newSt = StringUtils.replace(newSt, "#", "##");

                 if (i > 0)

                 {

                     result.append("#");

                 }

                 result.append(newSt);

             }

             return result.toString();

         }

         catch (ClassCastException e)

         {

             throw new ConversionException("Object is not a List of String it is a"

                     + source.getClass().getName());

         }

     }

     /* (non-Javadoc)

      * @see org.apache.ojb.broker.accesslayer.conversions.FieldConversion#sqlToJava(java.lang.Object)

      */

     public Object sqlToJava(Object source) throws ConversionException

     {

         if (source == null)

         {

             return null;

         }

         if (source.toString().equals(NULLVALUE))

         {

             return null;

         }

         if (source.toString().equals(EMPTYCOLLEC))

         {

             return new ArrayList();

         }

         List v = new ArrayList();

         StringBuffer input = new StringBuffer();

         StringBuffer newString = new StringBuffer();

         int pos = 0;

         int length;

         input.append(source.toString());

         length = input.length();

         while (pos < length)

         {

             if (input.charAt(pos) != '#')

             {

                 newString.append(input.charAt(pos));

             }

             else

             {

                 if (input.charAt(pos + 1) != '#')

                 {

                     v.add(newString.toString());

                     newString = new StringBuffer();

                 }

                 else

                 {

                     newString.append('#');

                     ++pos;

                 }

             }

             ++pos;

         }

         v.add(newString.toString());

         return v;

     }

 }