| /* |
| * Copyright (C) 2009-2010, Google Inc. |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package org.eclipse.jgit.http.server.glue; |
| |
| import java.io.IOException; |
| import java.util.Enumeration; |
| import java.util.NoSuchElementException; |
| import java.util.Set; |
| |
| import javax.servlet.Filter; |
| import javax.servlet.FilterChain; |
| import javax.servlet.ServletConfig; |
| import javax.servlet.ServletContext; |
| import javax.servlet.ServletException; |
| import javax.servlet.ServletRequest; |
| import javax.servlet.ServletResponse; |
| import javax.servlet.http.HttpServlet; |
| import javax.servlet.http.HttpServletRequest; |
| import javax.servlet.http.HttpServletResponse; |
| |
| /** |
| * Encapsulates the entire serving stack for a single URL. |
| * <p> |
| * Subclasses provide the implementation of {@link #match(HttpServletRequest)}, |
| * which is called by {@link MetaServlet} in registration order to determine the |
| * pipeline that will be used to handle a request. |
| * <p> |
| * The very bottom of each pipeline is a single {@link HttpServlet} that will |
| * handle producing the response for this pipeline's URL. {@link Filter}s may |
| * also be registered and applied around the servlet's processing, to manage |
| * request attributes, set standard response headers, or completely override the |
| * response generation. |
| */ |
| abstract class UrlPipeline { |
| /** Filters to apply around {@link #servlet}; may be empty but never null. */ |
| private final Filter[] filters; |
| |
| /** Instance that must generate the response; never null. */ |
| private final HttpServlet servlet; |
| |
| UrlPipeline(final Filter[] filters, final HttpServlet servlet) { |
| this.filters = filters; |
| this.servlet = servlet; |
| } |
| |
| /** |
| * Initialize all contained filters and servlets. |
| * |
| * @param context |
| * the servlet container context our {@link MetaServlet} is |
| * running within. |
| * @param inited |
| * <i>(input/output)</i> the set of filters and servlets which |
| * have already been initialized within the container context. If |
| * those same instances appear in this pipeline they are not |
| * initialized a second time. Filters and servlets that are first |
| * initialized by this pipeline will be added to this set. |
| * @throws ServletException |
| * a filter or servlet is unable to initialize. |
| */ |
| void init(final ServletContext context, final Set<Object> inited) |
| throws ServletException { |
| for (Filter ref : filters) |
| initFilter(ref, context, inited); |
| initServlet(servlet, context, inited); |
| } |
| |
| private static void initFilter(final Filter ref, |
| final ServletContext context, final Set<Object> inited) |
| throws ServletException { |
| if (!inited.contains(ref)) { |
| ref.init(new NoParameterFilterConfig(ref.getClass().getName(), |
| context)); |
| inited.add(ref); |
| } |
| } |
| |
| private static void initServlet(final HttpServlet ref, |
| final ServletContext context, final Set<Object> inited) |
| throws ServletException { |
| if (!inited.contains(ref)) { |
| ref.init(new ServletConfig() { |
| @Override |
| public String getInitParameter(String name) { |
| return null; |
| } |
| |
| @Override |
| public Enumeration<String> getInitParameterNames() { |
| return new Enumeration<String>() { |
| @Override |
| public boolean hasMoreElements() { |
| return false; |
| } |
| |
| @Override |
| public String nextElement() { |
| throw new NoSuchElementException(); |
| } |
| }; |
| } |
| |
| @Override |
| public ServletContext getServletContext() { |
| return context; |
| } |
| |
| @Override |
| public String getServletName() { |
| return ref.getClass().getName(); |
| } |
| }); |
| inited.add(ref); |
| } |
| } |
| |
| /** |
| * Destroy all contained filters and servlets. |
| * |
| * @param destroyed |
| * <i>(input/output)</i> the set of filters and servlets which |
| * have already been destroyed within the container context. If |
| * those same instances appear in this pipeline they are not |
| * destroyed a second time. Filters and servlets that are first |
| * destroyed by this pipeline will be added to this set. |
| */ |
| void destroy(final Set<Object> destroyed) { |
| for (Filter ref : filters) |
| destroyFilter(ref, destroyed); |
| destroyServlet(servlet, destroyed); |
| } |
| |
| private static void destroyFilter(Filter ref, Set<Object> destroyed) { |
| if (!destroyed.contains(ref)) { |
| ref.destroy(); |
| destroyed.add(ref); |
| } |
| } |
| |
| private static void destroyServlet(HttpServlet ref, Set<Object> destroyed) { |
| if (!destroyed.contains(ref)) { |
| ref.destroy(); |
| destroyed.add(ref); |
| } |
| } |
| |
| /** |
| * Determine if this pipeline handles the request's URL. |
| * <p> |
| * This method should match on the request's {@code getPathInfo()} method, |
| * as {@link MetaServlet} passes the request along as-is to each pipeline's |
| * match method. |
| * |
| * @param req |
| * current HTTP request being considered by {@link MetaServlet}. |
| * @return {@code true} if this pipeline is configured to handle the |
| * request; {@code false} otherwise. |
| */ |
| abstract boolean match(HttpServletRequest req); |
| |
| /** |
| * Execute the filters and the servlet on the request. |
| * <p> |
| * Invoked by {@link MetaServlet} once {@link #match(HttpServletRequest)} |
| * has determined this pipeline is the correct pipeline to handle the |
| * current request. |
| * |
| * @param req |
| * current HTTP request. |
| * @param rsp |
| * current HTTP response. |
| * @throws ServletException |
| * request cannot be completed. |
| * @throws IOException |
| * IO error prevents the request from being completed. |
| */ |
| void service(HttpServletRequest req, HttpServletResponse rsp) |
| throws ServletException, IOException { |
| if (0 < filters.length) |
| new Chain(filters, servlet).doFilter(req, rsp); |
| else |
| servlet.service(req, rsp); |
| } |
| |
| private static class Chain implements FilterChain { |
| private final Filter[] filters; |
| |
| private final HttpServlet servlet; |
| |
| private int filterIdx; |
| |
| Chain(final Filter[] filters, final HttpServlet servlet) { |
| this.filters = filters; |
| this.servlet = servlet; |
| } |
| |
| @Override |
| public void doFilter(ServletRequest req, ServletResponse rsp) |
| throws IOException, ServletException { |
| if (filterIdx < filters.length) |
| filters[filterIdx++].doFilter(req, rsp, this); |
| else |
| servlet.service(req, rsp); |
| } |
| } |
| } |