i18nfactoryset.java

这是一个轻便的j2ee的web应用框架,是一个在多个项目中运用的实际框架,采用struts,hebinate,xml等技术,有丰富的tag,role,navigation,session,dictio

    DefinitionsFactory factory = new DefinitionsFactory( rootXmlConfig );
    if(log.isDebugEnabled())
      log.debug( "factory loaded : " + factory );

    return factory;
    }

  /**
   * Extract key that will be used to get the sub factory.
   * @param name Name of requested definition
   * @param request Current servlet request.
   * @param servletContext Current servlet context.
   * @return the key or <code>null</code> if not found.
   */
  protected Object getDefinitionsFactoryKey(String name, ServletRequest request, ServletContext servletContext)
  {
  Locale locale = null;
  try
    {
    HttpSession session = ((HttpServletRequest)request).getSession(false);
    if (session != null)
      locale = (Locale)session.getAttribute(DefinitionsUtil.LOCALE_KEY);
    }
   catch( ClassCastException ex )
    { //
    log.error( "I18nFactorySet.getDefinitionsFactoryKey" );
    ex.printStackTrace();
    }

  return locale;
  }

   /**
    * Create a factory for specified key.
   * If creation failes, return default factory and log an error message.
   * @param key The key.
   * @param request Servlet request.
   * @param servletContext Servlet context.
   * @return Definition factory for specified key.
   * @throws DefinitionsFactoryException If an error occur while creating factory.
    */
  protected DefinitionsFactory createFactory(Object key, ServletRequest request, ServletContext servletContext)
    throws DefinitionsFactoryException
    {
    if( key == null )
      return getDefaultFactory();


      // Build possible postfixes
    List possiblePostfixes = calculatePostixes( "", (Locale)key );


      // Search last postix corresponding to a config file to load.
      // First check if something is loaded for this postfix.
      // If not, try to load its config.
    XmlDefinitionsSet lastXmlFile = null;
    DefinitionsFactory factory = null;
    String curPostfix = null;
    int i;

    for(i=possiblePostfixes.size()-1; i>=0; i-- )
      {
      curPostfix = (String)possiblePostfixes.get(i);
        // Already loaded ?
      factory = (DefinitionsFactory)loaded.get( curPostfix );
      if( factory != null )
        { // yes, stop search
        return factory;
        } // end if
        // Try to load it. If success, stop search
      lastXmlFile = parseXmlFiles( servletContext, curPostfix, null );
      if( lastXmlFile != null )
        break;
      } // end loop

      // Have we found a description file ?
      // If no, return default one
    if( lastXmlFile == null )
      {
      return getDefaultFactory();
      }

      // We found something. Need to load base and intermediate files
    String lastPostfix = curPostfix;
    XmlDefinitionsSet rootXmlConfig = parseXmlFiles( servletContext, "", null );
    for( int j=0; j<i; j++ )
      {
      curPostfix = (String)possiblePostfixes.get(j);
      parseXmlFiles( servletContext, curPostfix, rootXmlConfig);
      } // end loop

    rootXmlConfig.extend( lastXmlFile );
    rootXmlConfig.resolveInheritances();

    factory = new DefinitionsFactory(rootXmlConfig);
    loaded.put( lastPostfix, factory );
      // Operator help
    if(log.isDebugEnabled())
      log.debug( "factory loaded : " + factory );
      // return last available found !
    return factory;
    }

    /**
     * Calculate the postixes along the search path from the base bundle to the
     * bundle specified by baseName and locale.
     * Method copied from java.util.ResourceBundle
     * @param baseName the base bundle name
     * @param locale the locale
     */
    private static List calculatePostixes(String baseName, Locale locale) {
        final List result = new ArrayList(MAX_BUNDLES_SEARCHED);
        final String language = locale.getLanguage();
        final int languageLength = language.length();
        final String country = locale.getCountry();
        final int countryLength = country.length();
        final String variant = locale.getVariant();
        final int variantLength = variant.length();

        if (languageLength + countryLength + variantLength == 0) {
            //The locale is "", "", "".
            return result;
        }
        final StringBuffer temp = new StringBuffer(baseName);
        temp.append('_');
        temp.append(language);

        if(languageLength > 0)
            result.add(temp.toString());

        if (countryLength + variantLength == 0)
            return result;

        temp.append('_');
        temp.append(country);

        if(countryLength > 0)
            result.add(temp.toString());

        if(variantLength == 0) {
            return result;
        } else {
            temp.append('_');
            temp.append(variant);
            result.add(temp.toString());
            return result;
        }
    }

    /**
     * Parse files associated to postix if they exist.
     * For each name in filenames, append postfix before file extension,
     * then try to load the corresponding file.
     * If file doesn't exist, try next one. Each file description is added to
     * the XmlDefinitionsSet description.
     * The XmlDefinitionsSet description is created only if there is a definition file.
     * Inheritance is not resolved in the returned XmlDefinitionsSet.
     * If no description file can be opened and no definiion set is provided, return <code>null</code>.
     * @param postfix Postfix to add to each description file.
     * @param xmlDefinitions Definitions set to which definitions will be added. If <code>null</code>, a definitions
     * set is created on request.
     * @return XmlDefinitionsSet The definitions set created or passed as parameter.
     * @throws DefinitionsFactoryException On errors parsing file.
     */
  private XmlDefinitionsSet parseXmlFiles( ServletContext servletContext, String postfix, XmlDefinitionsSet xmlDefinitions )
      throws DefinitionsFactoryException
    {
    if( postfix != null && postfix.length() == 0 )
      postfix = null;

      // Iterate throw each file name in list
    Iterator i = filenames.iterator();
    while( i.hasNext() )
      {
      String filename = concatPostfix((String)i.next(), postfix) ;
      xmlDefinitions = parseXmlFile( servletContext, filename, xmlDefinitions );
      } // end loop
    return xmlDefinitions;
    }

    /**
     * Parse specified xml file and add definition to specified definitions set.
     * This method is used to load several description files in one instances list.
     * If filename exists and definition set is <code>null</code>, create a new set. Otherwise, return
     * passed definition set (can be <code>null</code>).
     * @param servletContext Current servlet context. Used to open file.
     * @param filename Name of file to parse.
     * @param xmlDefinitions Definitions set to which definitions will be added. If null, a definitions
     * set is created on request.
     * @return XmlDefinitionsSet The definitions set created or passed as parameter.
     * @throws DefinitionsFactoryException On errors parsing file.
     */
  private XmlDefinitionsSet parseXmlFile( ServletContext servletContext, String filename , XmlDefinitionsSet xmlDefinitions)
      throws DefinitionsFactoryException
    {
    try
      {
	    InputStream input = servletContext.getResourceAsStream(filename);
        // Try to load using real path.
        // This allow to load config file under websphere 3.5.x
        // Patch proposed Houston, Stephen (LIT) on 5 Apr 2002
      if (null == input)
      {
        try
         {
         input = new java.io.FileInputStream(servletContext.getRealPath(filename));
         }
         catch (Exception e)
         {
         }
     }
        // If still nothing found, this mean no config file is associated
	    if(input == null )
        {
        if(log.isDebugEnabled())
          log.debug( "Can't open file '" + filename + "'" );
        return xmlDefinitions;
        }

        // Check if parser already exist.
        // Doesn't seem to work yet.
      //if( xmlParser == null )
      if( true )
        {  // create it
        //if(log.isDebugEnabled())
          //log.debug( "Create xmlParser");
        xmlParser = new XmlParser();
        xmlParser.setValidating(isValidatingParser);
        xmlParser.setDetailLevel(parserDetailLevel);
        }
        // Check if definition set already exist.
      if( xmlDefinitions == null )
        {  // create it
        //if(log.isDebugEnabled())
          //log.debug( "Create xmlDefinitions");
        xmlDefinitions = new XmlDefinitionsSet();
        }

      xmlParser.parse( input, xmlDefinitions );
	    }
	   catch( SAXException ex )
	    {
      if(log.isDebugEnabled())
        {
        log.debug( "Error while parsing file '"  + filename + "'.");
        ex.printStackTrace();
        }
	    throw new DefinitionsFactoryException( "Error while parsing file '" + filename + "'. " + ex.getMessage(), ex );
	    }
	   catch( IOException ex )
	    {
	    throw new DefinitionsFactoryException( "IO Error while parsing file '" + filename + "'. " + ex.getMessage(), ex);
	    }

    return xmlDefinitions;
    }

    /**
     * Concat postfix to the name. Take care of existing filename extension.
     * Transform the given name "name.ext" to have "name" + "postfix" + "ext".
     * If there is no ext, return "name" + "postfix".
     * @param name Filename.
     * @param postfix Postfix to add.
     * @return Concatenated filename.
     */
  private String concatPostfix( String name, String postfix )
    {
    if( postfix == null )
      return name;

      // Search file name extension.
      // take care of Unix files starting with .
    int dotIndex = name.lastIndexOf( "." );
    int lastNameStart = name.lastIndexOf( java.io.File.pathSeparator );
    if( dotIndex < 1 || dotIndex < lastNameStart )
      return name + postfix;

    String ext = name.substring( dotIndex );
    name = name.substring( 0, dotIndex);
    return name + postfix + ext;
    }

    /**
     * Return String representation.
     * @return String representation.
     */
  public String toString()
    {
    StringBuffer buff = new StringBuffer( "I18nFactorySet : \n" );
    buff.append( "--- default factory ---\n" );
    buff.append( defaultFactory.toString() );
    buff.append( "\n--- other factories ---\n" );
    Iterator i = factories.values().iterator();
    while( i.hasNext() )
      {
      buff.append( i.next().toString() ).append("---------- \n");
      }
    return buff.toString();
    }


}