SchemaStorage.java

/*
** Module   : SchemaStorage.java
** Abstract : Contains the metadata that defines the directory schema. 
**
** Copyright (c) 2005-2025, Golden Code Development Corporation.
**
** -#- -I- --Date-- --JPRM-- ----------------Description-----------------
** 001 SIY 20050418   @21033 Created initial version.
** 002 GES 20090515   @42208 Imports change.
** 003 GES 20101116          Allow schema loading from multiple XML input
**                           sources. These sources can be resources in a JAR
**                           or files in the filesystem.  The objective is to
**                           always obtain the core directory schema from a
**                           standard source that is part of the project, while
**                           still allowing custom extensions of the schema to
**                           be added in a specific implementation.
** 004 EVL 20160225          Javadoc fixes to make compatible with Oracle Java 8 for Solaris 10.
** 005 SP  20250416          Used CaseInsensitiveHashMap for list map. Code formatting and javadoc fixes.
*/

/*
** 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
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**   Affero GPL version 3 and may not be removed by you.
** 
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** 
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*/

package com.goldencode.p2j.directory;

import java.util.*;
import java.net.*;
import javax.naming.directory.*;
import org.w3c.dom.*;

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

/**
 * Holds the set of directory object definitions (instances of
 * {@link ObjectClass}) which represent the schema (structure) of the directory.
 */
class SchemaStorage
{
   /** XML attribute for the attribute "multiple" flag. */
   private static final String ATTR_MULT = "multiple";

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

   /** XML attribute for the attribute "mandatory" flag. */
   private static final String ATTR_MAND = "mandatory";

   /** XML attribute for the attribute "read-only" flag. */
   private static final String ATTR_RO = "immutable";

   /** XML attribute for the attribute "type" field. */
   private static final String ATTR_TYPE = "type";

   /** XML attribute for the class "leaf" flag. */
   private static final String ATTR_LEAF = "leaf";

   /** XML tag for the class element. */
   private static final String ELEM_CLASS = "object-class";

   /** XML tag for the class attribute element. */
   private static final String ELEM_CLASS_ATTR = "class-attribute";

   /** Singleton instance. */
   private static SchemaStorage schema = null;

   /** Directory object definitions (loaded once at startup and not changed). */
   private Map<String, ObjectClass> list = new CaseInsensitiveHashMap<>();
   
   /** Cached list of the keys in our map. */
   private String[] keys = null;

   /**
    * Construct an instance.  This is private to enforce the singleton pattern.
    * 
    * @param    urls
    *           List of XML resources from which the schema will be read.  The
    *           order of the array defines the order of loading.
    * @param    required
    *           List of object classes that must exist in the loaded schema.
    */
   private SchemaStorage(URL[] urls, String[] required)
   throws Exception
   {
      load(urls);
      checkRequiredClasses(required);
      initKeys();
   }

   /**
    * Get the singleton instance.
    * 
    * @return   Singleton instance.
    */
   static synchronized SchemaStorage getSchema()
   {
      return schema;
   }

   /**
    * Initialize the singleton instance.
    * 
    * @param    urls
    *           List of XML resources from which the schema will be read.  The
    *           order of the array defines the order of loading.
    * @param    required
    *           List of object classes that must exist in the loaded schema.
    *
    * @return   The singleton instance.
    *
    * @throws   Exception
    *           If an error occurred during schema initialization.
    */
   static synchronized SchemaStorage initSchema(URL[] urls, String[] required)
   throws Exception
   {
      if (schema == null)
      {
         schema = new SchemaStorage(urls, required);
      }
      return schema;
   }

   /**
    * Get list of class names.
    * 
    * @return   An array of names of the defined object classes
    */
   String[] getClassNames()
   {
      return keys;
   }
   
   /**
    * Get definition for the specified Object Class.
    * 
    * @param    name
    *           Name of the Object Class to locate.
    *
    * @return   Reference to <code>ObjectClass</code> or <code>null</code>
    *           if no such class defined.
    */
   ObjectClass getObjectClass(String name)
   {
      return list.get(name);
   }

   /**
    * Read the schema definitions and create the list of object classes.
    * 
    * @param    urls
    *           List of XML resources from which the schema will be read.  The
    *           order of the array defines the order of loading.
    */
   private void load(URL[] urls)
   throws Exception
   {
      for (URL url : urls)
      {
         loadWorker(url);
      }
      
      // TODO: why is this here? If needed, it should be added somewhere else.
      // add the special "ldapNode"
      {
         ObjectClass obj = new ObjectClass("ldapNode", false, false, 
            new AttributeDefinition[] 
            {
               /* name, type, mandatory, multiple, immutable */
               new AttributeDefinition("location", AttributeType.ATTR_STRING, 
                                       true, false, false),
               new AttributeDefinition("p2jclass", AttributeType.ATTR_STRING, 
                                       true, false, false),
            });
         
         list.put(obj.getName(), obj);
      }
   }
   
   /**
    * Read the given schema definition and add to the list of object classes.
    * 
    * @param    url
    *           XML resource from which the schema will be read.
    */
   private void loadWorker(URL url)
   throws Exception
   {
      Document dom = XmlHelper.parse(url.openStream());
      Element elem = dom.getDocumentElement();
      Node rootNode = elem.getFirstChild();

      if (rootNode == null)
      {
         String spec = "Missing root element in the XML file (%s).";
         throw new ConfigurationException(String.format(spec, url));
      }

      while (rootNode != null)
      {
         if (rootNode.getNodeName().equals(ELEM_CLASS))
         {
            elem = (Element)rootNode;

            String strName = elem.getAttribute(ATTR_NAME);
            String strLeaf = elem.getAttribute(ATTR_LEAF);
            String strRO = elem.getAttribute(ATTR_RO);

            if (strName == null || strLeaf == null || strRO == null)
            {
               continue;
            }

            NodeList attr = rootNode.getChildNodes();

            Vector<AttributeDefinition> attrs = new Vector<>();
            AttributeDefinition[] lst = new AttributeDefinition[0];

            for (int j = 0; j < attr.getLength(); j++)
            {
               if (attr.item(j).getNodeName().equals(ELEM_CLASS_ATTR))
               {
                  elem = (Element)attr.item(j);
                  String attrName = elem.getAttribute(ATTR_NAME);
                  String attrRO = elem.getAttribute(ATTR_RO);
                  String attrMult = elem.getAttribute(ATTR_MULT);
                  String attrReq = elem.getAttribute(ATTR_MAND);
                  String attrType = elem.getAttribute(ATTR_TYPE);

                  attrs.add(new AttributeDefinition(attrName,
                                                    str2type(attrType),
                                                    str2bool(attrReq),
                                                    str2bool(attrMult),
                                                    str2bool(attrRO)));
               }
            }
            if (attrs.size() > 0)
            {
               lst = attrs.toArray(lst);
            }
            else
            {
               lst = null;
            }

            ObjectClass obj = new ObjectClass(strName, str2bool(strLeaf), str2bool(strRO), lst);
            list.put(strName, obj);
         }
         
         rootNode = rootNode.getNextSibling();
      }
   }
   
   /**
    * Check resulting schema for the presence of required classes.
    *
    * @param    required
    *           List of object classes that must exist in the loaded schema.
    * 
    * @throws   ConfigurationException
    *           In case if not all required classes are present in the schema.
    */
   private void checkRequiredClasses(String[] required)
   throws ConfigurationException
   {
      for (int i = 0; i < required.length; i++)
      {
         if (!list.containsKey(required[i]))
         {
            throw new ConfigurationException("Schema definition lacks " +
                                             " required " + required[i] +
                                             " object class.");
         }
      }
   }

   /**
    * Initialize the cached list of keys in our map.  Since the keys don't
    * change once the map is loaded, there is no reason to calculate the
    * list dynamically.  Instead, it is done once at initialization time
    * and the results are saved off.  This increases runtime performance.
    */
   private void initKeys()
   {
      keys = new String[list.size() - 1];
      
      int i = 0;
      for (String key : list.keySet())
      {
         // TODO: why is this here?
         // hide the special ldap node key
         if ("ldapNode".equals(key))
         {
            continue;
         }
         keys[i++] = key;
      }
   }

   /**
   * Convert type name into type code using {@link AttributeType#fromString}.
    * 
    * @param    type
    *           Type name.
    *
    * @return   Type code restored from type name.
    *           
    * @throws   InvalidAttributesException
    *           If no such type name exists.
    */
   private int str2type(String type)
   throws InvalidAttributesException
   {
      int res = AttributeType.fromString(type);
      if (res == 0)
      {
         throw new InvalidAttributesException("Invalid attribute type [" + type + "]");
      }
      return res;
   }

   /**
    * Convert string into boolean value. Only a string which contains text
    * "true" (case does not matter) is converted into <code>true</code>.
    * 
    * @param    str
    *           Source string.
    *
    * @return   Converted boolean value from the given string.
    */
   private static boolean str2bool(String str)
   {
      return Boolean.valueOf(str).booleanValue();
   }
}