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- /*
- * 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() {
- public String getInitParameter(String name) {
- return null;
- }
-
- public Enumeration<String> getInitParameterNames() {
- return new Enumeration<String>() {
- public boolean hasMoreElements() {
- return false;
- }
-
- public String nextElement() {
- throw new NoSuchElementException();
- }
- };
- }
-
- public ServletContext getServletContext() {
- return context;
- }
-
- 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;
- }
-
- 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);
- }
- }
- }
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