//
// ========================================================================
// 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.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.util.annotation.ManagedAttribute;
import org.eclipse.jetty.util.annotation.ManagedObject;
/* ------------------------------------------------------------ */
/** A <code>HandlerWrapper</code> acts as a {@link Handler} but delegates the {@link Handler#handle handle} method and
* {@link LifeCycle life cycle} events to a delegate. This is primarily used to implement the <i>Decorator</i> pattern.
*
*/
@ManagedObject("Handler wrapping another Handler")
public class HandlerWrapper extends AbstractHandlerContainer
{
protected Handler _handler;
/* ------------------------------------------------------------ */
/**
*
*/
public HandlerWrapper()
{
}
/* ------------------------------------------------------------ */
/**
* @return Returns the handlers.
*/
@ManagedAttribute(value="Wrapped Handler", readonly=true)
public Handler getHandler()
{
return _handler;
}
/* ------------------------------------------------------------ */
/**
* @return Returns the handlers.
*/
@Override
public Handler[] getHandlers()
{
if (_handler==null)
return new Handler[0];
return new Handler[] {_handler};
}
/* ------------------------------------------------------------ */
/**
* @param handler Set the {@link Handler} which should be wrapped.
*/
public void setHandler(Handler handler)
{
if (isStarted())
throw new IllegalStateException(STARTED);
if (handler!=null)
handler.setServer(getServer());
Handler old=_handler;
_handler=handler;
updateBean(old,_handler);
}
/* ------------------------------------------------------------ */
/** Replace the current handler with another HandlerWrapper
* linked to the current handler. This is equivalent to:<pre>
* wrapper.setHandler(getHandler());
* setHandler(wrapper);
* </pre>
* @param wrapper
*/
public void insertHandler(HandlerWrapper wrapper)
{
if (wrapper==null || wrapper.getHandler()!=null)
throw new IllegalArgumentException();
wrapper.setHandler(getHandler());
setHandler(wrapper);
}
/* ------------------------------------------------------------ */
@Override
public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
{
if (_handler!=null && isStarted())
{
_handler.handle(target,baseRequest, request, response);
}
}
/* ------------------------------------------------------------ */
@Override
public void setServer(Server server)
{
if (server==getServer())
return;
if (isStarted())
throw new IllegalStateException(STARTED);
super.setServer(server);
Handler h=getHandler();
if (h!=null)
h.setServer(server);
}
/* ------------------------------------------------------------ */
@Override
protected void expandChildren(List<Handler> list, Class<?> byClass)
{
expandHandler(_handler,list,byClass);
}
/* ------------------------------------------------------------ */
@Override
public void destroy()
{
if (!isStopped())
throw new IllegalStateException("!STOPPED");
Handler child=getHandler();
if (child!=null)
{
setHandler(null);
child.destroy();
}
super.destroy();
}
}