//
// ========================================================================
// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.server.handler;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.HandlerContainer;
/* ------------------------------------------------------------ */
/** Abstract Handler Container.
* This is the base class for handlers that may contain other handlers.
*
*/
public abstract class AbstractHandlerContainer extends AbstractHandler implements HandlerContainer
{
/* ------------------------------------------------------------ */
public AbstractHandlerContainer()
{
}
/* ------------------------------------------------------------ */
@Override
public Handler[] getChildHandlers()
{
List<Handler> list=new ArrayList<>();
expandChildren(list,null);
return list.toArray(new Handler[list.size()]);
}
/* ------------------------------------------------------------ */
@Override
public Handler[] getChildHandlersByClass(Class<?> byclass)
{
List<Handler> list=new ArrayList<>();
expandChildren(list,byclass);
return list.toArray(new Handler[list.size()]);
}
/* ------------------------------------------------------------ */
@Override
public <T extends Handler> T getChildHandlerByClass(Class<T> byclass)
{
List<Handler> list=new ArrayList<>();
expandChildren(list,byclass);
if (list.isEmpty())
return null;
return (T)list.get(0);
}
/* ------------------------------------------------------------ */
protected void expandChildren(List<Handler> list, Class<?> byClass)
{
}
/* ------------------------------------------------------------ */
protected void expandHandler(Handler handler, List<Handler> list, Class<?> byClass)
{
if (handler==null)
return;
if (byClass==null || byClass.isAssignableFrom(handler.getClass()))
list.add(handler);
if (handler instanceof AbstractHandlerContainer)
((AbstractHandlerContainer)handler).expandChildren(list, byClass);
else if (handler instanceof HandlerContainer)
{
HandlerContainer container = (HandlerContainer)handler;
Handler[] handlers=byClass==null?container.getChildHandlers():container.getChildHandlersByClass(byClass);
list.addAll(Arrays.asList(handlers));
}
}
/* ------------------------------------------------------------ */
public static <T extends HandlerContainer> T findContainerOf(HandlerContainer root,Class<T>type, Handler handler)
{
if (root==null || handler==null)
return null;
Handler[] branches=root.getChildHandlersByClass(type);
if (branches!=null)
{
for (Handler h:branches)
{
T container = (T)h;
Handler[] candidates = container.getChildHandlersByClass(handler.getClass());
if (candidates!=null)
{
for (Handler c:candidates)
if (c==handler)
return container;
}
}
}
return null;
}
}