# DatabaseReferenceWorker.java

    /*
    ** Module   : DatabaseReferenceWorker.java
    ** Abstract : Helper routines for unreferenced tables/fields processing.
    **
    ** Copyright (c) 2005-2017, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --JPRM-- ----------------------------Description-----------------------------
    ** 001 SIY 20050724   @21992 Created initial version.
    ** 002 GES 20080318   @37638 Switched from writer to stream to avoid
    **                           unwanted character conversion when the
    **                           default character set is not 8-bit ASCII.
    ** 003 GES 20090515   @42205 Import changes.
    ** 004 IAS 20160331          Add input stream's close
    **/

    package com.goldencode.p2j.convert;

    import java.io.*;
    import java.util.*;

    import javax.xml.parsers.*;
    import org.w3c.dom.*;
    import org.xml.sax.*;

    import com.goldencode.p2j.pattern.*;
    import com.goldencode.util.*;

    /**
     * Helper routines for the unreferenced tables/fields rule set.
     */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */
    public final class DatabaseReferenceWorker
    extends AbstractPatternWorker
    {
       /**
        * Default constructor which initializes libraries.
        */
       public DatabaseReferenceWorker()
       {
          super();
          setLibrary(new Helper());
       }

       /**
        * Provides user-level APIs necessary for unreferenced tables/fields
        * processing.
        */
       public class Helper
       {
          /** XML tag for the root element */
          private static final String ELEM_TAG_ROOT  = "temporary-data";

          /** XML tag for the table element */
          private static final String ELEM_TAG_TABLE = "table";

          /** XML tag for the field element */
          private static final String ELEM_TAG_FIELD = "field";

          /** XML attribute for the table and field name */
          private static final String ATTR_NAME = "name";

          /**
           * Store map into the XML file.
           * <p>
           * Each map element represents a table referenced by Progress code
           * and holds another map which contains fields referenced.
           *
           * @param   map
           *          Map which describes referenced tables and fields.
           * @param   file
           *          XML file name.
           *
           * @return  <code>true</code> if operation was successful.
           *
           * @throws  ParserConfigurationException
           *          forwarded from <code>XmlHelper</code> methods.
           */
          public boolean persistMap(Map map, String file)
          throws ParserConfigurationException
          {
             Document dom = XmlHelper.newDocument();

             //Add comments
             Comment comment;

             comment = dom.createComment("DatabaseReferenceWorker temporary file");
             dom.appendChild(comment);

             comment = dom.createComment("Saved " + (new Date()));
             dom.appendChild(comment);

             Element root = dom.createElement(ELEM_TAG_ROOT);
             dom.appendChild(root);

             Iterator iter = new TreeSet(map.keySet()).iterator();

             while(iter.hasNext())
             {
                Element elem     = dom.createElement(ELEM_TAG_TABLE);
                String tableName = (String) iter.next();
                Map table        = (Map) map.get(tableName);
                Iterator fields  = (new TreeSet(table.keySet())).iterator();

                elem.setAttribute(ATTR_NAME, tableName);

                root.appendChild(elem);

                while(fields.hasNext())
                {
                   String fieldName = (String) fields.next();

                   Element nodeAttr = dom.createElement(ELEM_TAG_FIELD);

                   nodeAttr.setAttribute(ATTR_NAME, fieldName);

                   elem.appendChild(nodeAttr);
                }
             }

             try
             {
                XmlHelper.write(dom, file);
             }
             catch (IOException e)
             {
                return false;
             }

             return true;
          }

          /**
           * Restore map which contains information about referenced tables and
           * fields from XML.
           *
           * @param   file
           *          XML file name.
           *
           * @return  an instance of <code>Map</code> if operation was successful
           *          or <code>null</code> if not.
           *
           * @throws  SAXException
           *          forwarded from <code>XmlHelper</code> methods.
           * @throws  IOException
           *          forwarded from <code>XmlHelper</code> methods.
           * @throws  ParserConfigurationException
           *          forwarded from <code>XmlHelper</code> methods.
           * @throws  FileNotFoundException
           *          forwarded from <code>XmlHelper</code> methods.
           */
          public Map loadMap(String file)
          throws FileNotFoundException,
                 ParserConfigurationException,
                 IOException,
                 SAXException
          {
             FileInputStream in = new FileInputStream(file);
             try
             {
                Document dom = XmlHelper.parse(in);
                Node node    = dom.getDocumentElement().getFirstChild();
                HashMap res  = new HashMap();

                while (node != null)
                {
                   if (node.getNodeName().equals(ELEM_TAG_TABLE))
                   {
                      Element elem   = (Element) node;
                      String name    = elem.getAttribute(ATTR_NAME);
                      HashMap fields = new HashMap();

                      NodeList l = node.getChildNodes();

                      for (int i = 0; i < l.getLength(); i++)
                      {
                         if (l.item(i).getNodeName().equals(ELEM_TAG_FIELD))
                         {
                            elem = (Element) l.item(i);

                            String fieldName = elem.getAttribute(ATTR_NAME);

                            if (fieldName == null)
                               return null;

                            fields.put(fieldName, fieldName);
                         }
                      }

                      res.put(name, fields);
                   }

                   node = node.getNextSibling();
                }

                return res;
             }
             finally
             {
                in.close();
             }

          }
       }
    }