| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hdfsproxy; |
| |
| import java.io.IOException; |
| |
| import javax.servlet.RequestDispatcher; |
| import javax.servlet.ServletContext; |
| import javax.servlet.ServletException; |
| import javax.servlet.http.HttpServlet; |
| import javax.servlet.http.HttpServletRequest; |
| import javax.servlet.http.HttpServletResponse; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| |
| /** |
| * |
| * |
| */ |
| public class ProxyForwardServlet extends HttpServlet { |
| /** |
| * |
| */ |
| private static final long serialVersionUID = 1L; |
| private static Configuration configuration = null; |
| public static final Log LOG = LogFactory.getLog(ProxyForwardServlet.class); |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void init() throws ServletException { |
| ServletContext context = getServletContext(); |
| configuration = (Configuration) context |
| .getAttribute("org.apache.hadoop.hdfsproxy.conf"); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void doGet(HttpServletRequest request, HttpServletResponse response) |
| throws IOException, ServletException { |
| String hostname = request.getServerName(); |
| |
| String version = configuration.get(hostname); |
| if (version == null) { |
| // extract from hostname directly |
| String[] strs = hostname.split("[-\\.]"); |
| version = "/" + strs[0]; |
| } |
| |
| ServletContext curContext = getServletContext(); |
| ServletContext dstContext = curContext.getContext(version); |
| |
| // avoid infinite forwarding. |
| if (dstContext == null |
| || getServletContext().equals(dstContext)) { |
| LOG.error("Context (" + version |
| + ".war) non-exist or restricted from access"); |
| response.sendError(HttpServletResponse.SC_NOT_FOUND); |
| return; |
| } |
| LOG.debug("Request to " + hostname + " is forwarded to version " + version); |
| forwardRequest(request, response, dstContext, request.getServletPath()); |
| |
| } |
| |
| /** {@inheritDoc} */ |
| public void forwardRequest(HttpServletRequest request, |
| HttpServletResponse response, ServletContext context, String pathInfo) |
| throws IOException, ServletException { |
| String path = buildForwardPath(request, pathInfo); |
| RequestDispatcher dispatcher = context.getRequestDispatcher(path); |
| if (dispatcher == null) { |
| LOG.info("There was no such dispatcher: " + path); |
| response.sendError(HttpServletResponse.SC_NO_CONTENT); |
| return; |
| } |
| dispatcher.forward(request, response); |
| } |
| |
| /** {@inheritDoc} */ |
| protected String buildForwardPath(HttpServletRequest request, String pathInfo) { |
| String path = pathInfo; |
| if (request.getPathInfo() != null) { |
| path += request.getPathInfo(); |
| } |
| if (request.getQueryString() != null) { |
| path += "?" + request.getQueryString(); |
| } |
| return path; |
| } |
| } |