definitionsutil.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

   * return it. If no, create a new one.
   * <p>
   * If checkIfExist is false, factory is always created.
   * <p>
   * Convenience method. Calls createDefinitionsFactory(ServletContext servletContext, DefinitionsFactoryConfig factoryConfig)
   *
   * @param servletContext Servlet Context passed to newly created factory.
   * @param servletConfig Servlet config containing parameters to be passed to factory configuration object.
   * @param checkIfExist Check if factory already exist. If true and factory exist, return it.
   * If true and factory doesn't exist, create it. If false, create it in all cases.
   * @return newly created factory of type ConfigurableDefinitionsFactory.
   * @throws DefinitionsFactoryException If an error occur while initializing factory
   */
  public static DefinitionsFactory createDefinitionsFactory(ServletContext servletContext, ServletConfig servletConfig, boolean checkIfExist)
    throws DefinitionsFactoryException
  {
  if( checkIfExist )
    {
      // Check if already exist in context
    DefinitionsFactory factory = getDefinitionsFactory( servletContext);
    if( factory != null )
      return factory;
    }
    // creation
  return createDefinitionsFactory( servletContext, servletConfig);
  }

  /**
   * Create Definition factory from provided classname.
   * Factory class must extends TilesDefinitionsFactory.
   * @deprecated No direct replacement. Use createDefinitionFactory
   * {@link TilesUtil#createDefinitionsFactory(ServletContext, DefinitionsFactoryConfig)}.
   * @param classname Class name of the factory to create.
   * @return newly created factory.
   * @throws DefinitionsFactoryException If an error occur while initializing factory
   */
  static public DefinitionsFactory createDefinitionFactoryInstance(String classname)
    throws DefinitionsFactoryException
  {
  try
    {
    Class factoryClass = applicationClass(classname);
    Object factory = factoryClass.newInstance();
      // Backward compatibility : if factory classes implements old interface,
      // provide appropriate wrapper
    if( factory instanceof ComponentDefinitionsFactory )
      {
      factory = new ComponentDefinitionsFactoryWrapper( (ComponentDefinitionsFactory)factory );
      } // end if
    return (DefinitionsFactory)factory;
    }
   catch( ClassCastException ex )
    { // Bad classname
    throw new DefinitionsFactoryException( "Error - createDefinitionsFactory : Factory class '"
                                           + classname +" must implements 'TilesDefinitionsFactory'.", ex );
    }
   catch( ClassNotFoundException ex )
    { // Bad classname
    throw new DefinitionsFactoryException( "Error - createDefinitionsFactory : Bad class name '"
                                           + classname +"'.", ex );
    }
   catch( InstantiationException ex )
    { // Bad constructor or error
    throw new DefinitionsFactoryException( ex );
    }
   catch( IllegalAccessException ex )
    { //
    throw new DefinitionsFactoryException( ex );
    }

  }

  /**
   * Set definition factory in appropriate servlet context.
   * @param factory Factory to store.
   * @param servletContext Servlet context that will hold factory.
   * @deprecated since 20020708. Replaced by makeFactoryAccessible()
   */
  static protected void setDefinitionsFactory(ComponentDefinitionsFactory factory, ServletContext servletContext)
  {
  servletContext.setAttribute(DEFINITIONS_FACTORY, factory);
  }

  /**
   * Get a component / template definition by its name.
   * First, retrieve instance factory, and then get requested instance.
   * Throw appropriate exception if definition is not found.
   * @deprecated Use {@link TilesUtil#getDefinition(String, ServletRequest, ServletContext)}
   * @param definitionName Name of requested definition.
   * @param pageContext Current pageContext
   * @throws FactoryNotFoundException Can't find definition factory.
   * @throws DefinitionsFactoryException General error in factory while getting definition.
   * @throws NoSuchDefinitionException No definition found for specified name
   */
  static public ComponentDefinition getDefinition(String definitionName, PageContext pageContext)
    throws FactoryNotFoundException, DefinitionsFactoryException
  {
  return getDefinition( definitionName,
                        (HttpServletRequest)pageContext.getRequest(),
                        pageContext.getServletContext());
  }

  /**
   * Get definition factory from appropriate servlet context.
   * @return Definitions factory or null if not found.
   * @deprecated Use {@link TilesUtil#getDefinitionsFactory(ServletRequest, ServletContext)}
   * @since 20020708
   */
 static  public DefinitionsFactory getDefinitionsFactory(ServletContext servletContext)
  {
  return (DefinitionsFactory)servletContext.getAttribute(DEFINITIONS_FACTORY);
  }

  /**
   * Make definition factory accessible to Tags.
   * Factory is stored in servlet context.
   * @deprecated Use {@link TilesUtil#createDefinitionsFactory(ServletContext, DefinitionsFactoryConfig)}
   * @param factory Factory to make accessible
   * @param servletContext Current servlet context
   * @since 20020708
   */
 static  public void makeDefinitionsFactoryAccessible(DefinitionsFactory factory, ServletContext servletContext)
  {
  servletContext.setAttribute(DEFINITIONS_FACTORY, factory);
  }

  /**
   * Get Definition stored in jsp context by an action.
   * @return ComponentDefinition or null if not found.
   */
 static  public ComponentDefinition getActionDefinition(ServletRequest request)
  {
  return (ComponentDefinition)request.getAttribute(ACTION_DEFINITION);
  }

  /**
   * Store definition in jsp context.
   * Mainly used by Struts to pass a definition defined in an Action to the forward.
   */
 static  public void setActionDefinition(ServletRequest request, ComponentDefinition definition)
  {
  request.setAttribute(ACTION_DEFINITION, definition);
  }

  /**
   * Remove Definition stored in jsp context.
   * Mainly used by Struts to pass a definition defined in an Action to the forward.
   */
 static  public void removeActionDefinition(ServletRequest request, ComponentDefinition definition)
  {
  request.removeAttribute(ACTION_DEFINITION);
  }

  /**
   * Populate Definition Factory Config from web.xml properties.
   * @param factoryConfig Definition Factory Config to populate.
   * @param servletConfig Current servlet config containing web.xml properties.
   * @exception IllegalAccessException if the caller does not have
   *  access to the property accessor method
   * @exception java.lang.reflect.InvocationTargetException if the property accessor method
   *  throws an exception
   * @see org.apache.commons.beanutils.BeanUtils
   * @since tiles 20020708
   */
  static public void populateDefinitionsFactoryConfig( DefinitionsFactoryConfig factoryConfig, ServletConfig servletConfig)
    throws java.lang.IllegalAccessException,java.lang.reflect.InvocationTargetException
  {
  Map properties = new DefinitionsUtil.ServletPropertiesMap( servletConfig );
  factoryConfig.populate( properties);
  }

  /**
   * Create FactoryConfig and initialize it from web.xml.
   *
   * @param servletConfig ServletConfig for the module with which
   *  this plug in is associated
   * @exception DefinitionsFactoryException if this <code>PlugIn</code> cannot
   *  be successfully initialized
   */
  static protected DefinitionsFactoryConfig readFactoryConfig(ServletConfig servletConfig)
      throws DefinitionsFactoryException
  {
    // Create tiles definitions config object
  DefinitionsFactoryConfig factoryConfig = new DefinitionsFactoryConfig();
    // Get init parameters from web.xml files
  try
    {
    DefinitionsUtil.populateDefinitionsFactoryConfig(factoryConfig, servletConfig);
    }
   catch(Exception ex)
    {
    ex.printStackTrace();
    throw new DefinitionsFactoryException( "Can't populate DefinitionsFactoryConfig class from 'web.xml'.", ex );
    }
  return factoryConfig;
  }

  /**
   * Inner class.
   * Wrapper for ServletContext init parameters.
   * Object of this class is an hashmap containing parameters and values
   * defined in the servlet config file (web.xml).
   */
 static class ServletPropertiesMap extends HashMap {
    /**
     * Constructor.
     */
  ServletPropertiesMap( ServletConfig config )
    {
      // This implementation is very simple.
      // It is possible to avoid creation of a new structure, but this need
      // imply writing all Map interface.
    Enumeration enum = config.getInitParameterNames();
    while( enum.hasMoreElements() )
      {
      String key = (String)enum.nextElement();
      put( key, config.getInitParameter( key ) );
      }
    }
}  // end inner class

}