HostedSiteRequestFilter.java

/*******************************************************************************
 * Copyright (c) 2011, 2015 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.orion.server.hosting;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.eclipse.orion.internal.server.hosting.HostingActivator;
import org.eclipse.orion.internal.server.hosting.HostingConstants;
import org.eclipse.orion.internal.server.hosting.ISiteHostingService;

/**
 * If an incoming request is for a path on a running hosted site (based on Host header), 
 * this filter forwards the request to the {@link HostedSiteServlet} to be handled.
 */
public class HostedSiteRequestFilter implements Filter {

	private static final String HOSTED_SITE_ALIAS = "/hosted"; //$NON-NLS-1$

	private ISiteHostingService siteHostingService;

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		this.siteHostingService = HostingActivator.getDefault().getHostingService();
	}

	@Override
	public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
		if (siteHostingService != null) {
			HttpServletRequest httpReq = (HttpServletRequest) req;
			String host = getHost(httpReq);
			if (host != null) {
				String requestUri = httpReq.getRequestURI();
				String service = httpReq.getServletPath();
				boolean isForSite = siteHostingService.isHosted(host) || siteHostingService.matchesVirtualHost(host);
				// If the HostedSite handler has already forwarded this request, do not attempt to forward it again
				boolean alreadyForwarded = httpReq.getAttribute(HostingConstants.REQUEST_ATTRIBUTE_HOSTING_FORWARDED) != null;
				if (isForSite && !service.equals(HOSTED_SITE_ALIAS) && !alreadyForwarded) {
					// Forward to /hosted/<host>
					StringBuffer forward = new StringBuffer(HOSTED_SITE_ALIAS);
					forward.append('/');
					forward.append(host);
					forward.append(requestUri);
					String queryString = httpReq.getQueryString();
					if (queryString != null) {
						forward.append('?');
						forward.append(queryString);
					}
					RequestDispatcher rd = httpReq.getRequestDispatcher(forward.toString()); //$NON-NLS-1$
					rd.forward(req, resp);
					return;
				}
			}
		}
		chain.doFilter(req, resp);
	}

	private static String getHost(HttpServletRequest req) {
		String host = req.getHeader("Host"); //$NON-NLS-1$
		if (host != null) {
			int i = host.indexOf(":"); //$NON-NLS-1$
			if (i != -1)
				return host.substring(0, i);
		}
		return host;
	}

	@Override
	public void destroy() {
	}
}