001/*
002 * Sonar, open source software quality management tool.
003 * Copyright (C) 2008-2012 SonarSource
004 * mailto:contact AT sonarsource DOT com
005 *
006 * Sonar is free software; you can redistribute it and/or
007 * modify it under the terms of the GNU Lesser General Public
008 * License as published by the Free Software Foundation; either
009 * version 3 of the License, or (at your option) any later version.
010 *
011 * Sonar is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014 * Lesser General Public License for more details.
015 *
016 * You should have received a copy of the GNU Lesser General Public
017 * License along with Sonar; if not, write to the Free Software
018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019 */
020package org.sonar.server.platform;
021
022import com.google.common.annotations.VisibleForTesting;
023import com.google.common.base.Preconditions;
024import com.google.common.collect.Lists;
025import org.slf4j.LoggerFactory;
026import org.sonar.api.web.ServletFilter;
027
028import javax.servlet.*;
029import javax.servlet.http.HttpServletRequest;
030import java.io.IOException;
031import java.util.Iterator;
032import java.util.List;
033
034/**
035 * Inspired by http://stackoverflow.com/a/7592883/229031
036 */
037public class ServletFilters implements Filter {
038
039  private ServletFilter[] filters;
040
041  public void init(FilterConfig config) throws ServletException {
042    init(config, Platform.getInstance().getContainer().getComponentsByType(ServletFilter.class));
043  }
044
045  @VisibleForTesting
046  void init(FilterConfig config, List<ServletFilter> extensions) throws ServletException {
047    List<Filter> filterList = Lists.newArrayList();
048    for (ServletFilter extension : extensions) {
049      try {
050        LoggerFactory.getLogger(ServletFilters.class).info(String.format("Initializing servlet filter %s [pattern=%s]", extension, extension.doGetPattern()));
051        extension.init(config);
052        filterList.add(extension);
053      } catch (RuntimeException e) {
054        throw new IllegalStateException("Fail to initialize servlet filter: " + extension + ". Message: " + e.getMessage(), e);
055      }
056    }
057    filters = filterList.toArray(new ServletFilter[filterList.size()]);
058  }
059
060  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException, IOException {
061    HttpServletRequest hsr = (HttpServletRequest) request;
062    if (filters.length == 0) {
063      chain.doFilter(request, response);
064    } else {
065      String path = hsr.getRequestURI().replaceFirst(hsr.getContextPath(), "");
066      GodFilterChain godChain = new GodFilterChain(chain);
067
068      for (ServletFilter filter : filters) {
069        if (filter.doGetPattern().matches(path)) {
070          godChain.addFilter(filter);
071        }
072      }
073      godChain.doFilter(request, response);
074    }
075  }
076
077  public void destroy() {
078    for (ServletFilter filter : filters) {
079      filter.destroy();
080    }
081  }
082
083  @VisibleForTesting
084  ServletFilter[] getFilters() {
085    return filters;
086  }
087
088  private static final class GodFilterChain implements FilterChain {
089    private FilterChain chain;
090    private List<Filter> filters = Lists.newLinkedList();
091    private Iterator<Filter> iterator;
092
093    public GodFilterChain(FilterChain chain) {
094      this.chain = chain;
095    }
096
097    public void doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException {
098      if (iterator == null) {
099        iterator = filters.iterator();
100      }
101      if (iterator.hasNext()) {
102        iterator.next().doFilter(request, response, this);
103      } else {
104        chain.doFilter(request, response);
105      }
106    }
107
108    public void addFilter(Filter filter) {
109      Preconditions.checkState(iterator == null);
110      filters.add(filter);
111    }
112  }
113}