public DisplaytagColumnDecorator loadColumnDecorator(PageContext pageContext,
    String decoratorName) throws DecoratorInstantiationException 
{
        if (StringUtils.isBlank(decoratorName))
        {
            return null;
        }
        // first check: is decoratorName an object in page/request/session/application scope?
        Object decorator = pageContext.findAttribute(decoratorName);
        // second check: if a decorator was not found assume decoratorName is the class name and load it using
        // reflection
        if (decorator == null)
        {
            try
            {
                decorator = ReflectHelper.classForName(decoratorName).newInstance();
            }
            catch (ClassNotFoundException e)
            {
                throw new DecoratorInstantiationException(DefaultDecoratorFactory.class, decoratorName, e);
            }
            catch (InstantiationException e)
            {
                throw new DecoratorInstantiationException(DefaultDecoratorFactory.class, decoratorName, e);
            }
            catch (IllegalAccessException e)
            {
                throw new DecoratorInstantiationException(DefaultDecoratorFactory.class, decoratorName, e);
            }
        }
        if (decorator instanceof DisplaytagColumnDecorator)
        {
            return (DisplaytagColumnDecorator) decorator;
        }
        else if (decorator instanceof ColumnDecorator)
        {
            return new DeprecatedDecoratorWrapper((ColumnDecorator) decorator);
        }
        else
        {
            throw new DecoratorInstantiationException(
                DefaultDecoratorFactory.class,
                decoratorName,
                new ClassCastException(decorator.getClass().getName()));
        }
}

If the user has specified a column decorator, then this method takes care of creating the decorator (and checking to make sure it is a subclass of the DisplaytagColumnDecorator object). If there are any problems loading the decorator then this will throw a DecoratorInstantiationException which will get propagated up to the page.

Two different methods for loading a decorator are handled by this factory:

• First of all, an object with key decoratorName is searched in the page/request/session/scope
• If not found, assume decoratorName is the class name of the decorator and load it using reflection

 public TableDecorator loadTableDecorator(PageContext pageContext,
    String decoratorName) throws DecoratorInstantiationException 
{
        if (StringUtils.isBlank(decoratorName))
        {
            return null;
        }
        // first check: is decoratorName an object in page/request/session/application scope?
        Object decorator = pageContext.findAttribute(decoratorName);
        // second check: if a decorator was not found assume decoratorName is the class name and load it using
        // reflection
        if (decorator == null)
        {
            try
            {
                decorator = ReflectHelper.classForName(decoratorName).newInstance();
            }
            catch (ClassNotFoundException e)
            {
                throw new DecoratorInstantiationException(DefaultDecoratorFactory.class, decoratorName, e);
            }
            catch (InstantiationException e)
            {
                throw new DecoratorInstantiationException(DefaultDecoratorFactory.class, decoratorName, e);
            }
            catch (IllegalAccessException e)
            {
                throw new DecoratorInstantiationException(DefaultDecoratorFactory.class, decoratorName, e);
            }
        }
        if (decorator instanceof TableDecorator)
        {
            return (TableDecorator) decorator;
        }
        else
        {
            throw new DecoratorInstantiationException(
                DefaultDecoratorFactory.class,
                decoratorName,
                new ClassCastException(decorator.getClass().getName()));
        }
}

If the user has specified a decorator, then this method takes care of creating the decorator (and checking to make sure it is a subclass of the TableDecorator object). If there are any problems loading the decorator then this will throw a DecoratorInstantiationException which will get propagated up to the page.

Two different methods for loading a decorator are handled by this factory:

• First of all, an object with key decoratorName is searched in the page/request/session/scope
• If not found, assume decoratorName is the class name of the decorator and load it using reflection