001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020package org.crsh.vfs.spi.servlet;
021
022import org.crsh.util.Utils;
023import org.crsh.vfs.spi.AbstractFSDriver;
024
025import javax.servlet.ServletContext;
026import java.io.File;
027import java.io.FileInputStream;
028import java.io.IOException;
029import java.io.InputStream;
030import java.net.URL;
031import java.util.Collections;
032import java.util.Iterator;
033import java.util.Set;
034import java.util.regex.Matcher;
035import java.util.regex.Pattern;
036
037public class ServletContextDriver extends AbstractFSDriver<String> {
038
039  /** A valid path. */
040  static final Pattern pathPattern = Pattern.compile("^(?=/).*?((?<=/)[^/]*)?(/?)$");
041
042  /** . */
043  private final ServletContext ctx;
044
045  /** . */
046  private final String root;
047
048  public ServletContextDriver(ServletContext ctx, String root) {
049    if (ctx == null) {
050      throw new NullPointerException();
051    }
052    if (root == null) {
053      throw new NullPointerException();
054    }
055    assertMatch(root);
056
057    //
058    this.ctx = ctx;
059    this.root = root;
060  }
061
062  public String root() throws IOException {
063    return root;
064  }
065
066  public String name(String file) throws IOException {
067    return assertMatch(file).group(1);
068  }
069
070  public boolean isDir(String file) throws IOException {
071    Matcher matcher = assertMatch(file);
072    String slash = matcher.group(2);
073    return "/".equals(slash);
074  }
075
076  public Iterable<String> children(String parent) throws IOException {
077    @SuppressWarnings("unchecked")
078    Set<String> resourcePaths = (Set<String>)ctx.getResourcePaths(parent);
079    return resourcePaths != null ? resourcePaths : Collections.<String>emptyList();
080  }
081
082  /**
083   * The implementation attempts to get an URL that will be valid for the file system first (when the
084   * war is usually exploded) and if it is not able, it will delegate to {@link ServletContext#getResource(String)}.
085   *
086   * @param file the file path
087   * @return the URL
088   * @throws IOException any io exception
089   */
090  public URL toURL(String file) throws IOException {
091    String realPath = ctx.getRealPath(file);
092    if (realPath != null) {
093      File realFile = new File(realPath);
094      if (realFile.exists() && realFile.isFile()) {
095        return realFile.toURI().toURL();
096      }
097    }
098    return ctx.getResource(file);
099  }
100
101  public long getLastModified(String handle) throws IOException {
102    String realPath = ctx.getRealPath(handle);
103    if (realPath != null) {
104      File realFile = new File(realPath);
105      if (realFile.exists() && realFile.isFile()) {
106        return realFile.lastModified();
107      }
108    }
109    return ctx.getResource(handle).openConnection().getLastModified();
110  }
111
112  public Iterator<InputStream> open(String handle) throws IOException {
113    String realPath = ctx.getRealPath(handle);
114    if (realPath != null) {
115      File realFile = new File(realPath);
116      if (realFile.exists() && realFile.isFile()) {
117        return Utils.<InputStream>iterator(new FileInputStream(realFile));
118      }
119    }
120    return Utils.iterator(ctx.getResource(handle).openConnection().getInputStream());
121  }
122
123  private Matcher assertMatch(String path) {
124    Matcher m = pathPattern.matcher(path);
125    if (m.matches()) {
126      return m;
127    } else {
128      throw new IllegalArgumentException("Illegal path " + path);
129    }
130  }
131}