webdavservlet.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * 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.catalina.servlets;


import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Stack;
import java.util.TimeZone;
import java.util.Vector;

import javax.naming.NameClassPair;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.DirContext;
import javax.servlet.ServletException;
import javax.servlet.UnavailableException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.catalina.util.DOMWriter;
import org.apache.catalina.util.MD5Encoder;
import org.apache.catalina.util.RequestUtil;
import org.apache.catalina.util.XMLWriter;
import org.apache.naming.resources.CacheEntry;
import org.apache.naming.resources.Resource;
import org.apache.naming.resources.ResourceAttributes;
import org.apache.tomcat.util.http.FastHttpDateFormat;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;



/**
 * Servlet which adds support for WebDAV level 2. All the basic HTTP requests
 * are handled by the DefaultServlet.
 *
 * @author Remy Maucherat
 * @version $Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
 */

public class WebdavServlet
    extends DefaultServlet {


    // -------------------------------------------------------------- Constants


    private static final String METHOD_HEAD = "HEAD";
    private static final String METHOD_PROPFIND = "PROPFIND";
    private static final String METHOD_PROPPATCH = "PROPPATCH";
    private static final String METHOD_MKCOL = "MKCOL";
    private static final String METHOD_COPY = "COPY";
    private static final String METHOD_MOVE = "MOVE";
    private static final String METHOD_LOCK = "LOCK";
    private static final String METHOD_UNLOCK = "UNLOCK";


    /**
     * Default depth is infite.
     */
    private static final int INFINITY = 3; // To limit tree browsing a bit


    /**
     * PROPFIND - Specify a property mask.
     */
    private static final int FIND_BY_PROPERTY = 0;


    /**
     * PROPFIND - Display all properties.
     */
    private static final int FIND_ALL_PROP = 1;


    /**
     * PROPFIND - Return property names.
     */
    private static final int FIND_PROPERTY_NAMES = 2;


    /**
     * Create a new lock.
     */
    private static final int LOCK_CREATION = 0;


    /**
     * Refresh lock.
     */
    private static final int LOCK_REFRESH = 1;


    /**
     * Default lock timeout value.
     */
    private static final int DEFAULT_TIMEOUT = 3600;


    /**
     * Maximum lock timeout.
     */
    private static final int MAX_TIMEOUT = 604800;


    /**
     * Default namespace.
     */
    protected static final String DEFAULT_NAMESPACE = "DAV:";


    /**
     * Simple date format for the creation date ISO representation (partial).
     */
    protected static final SimpleDateFormat creationDateFormat =
        new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");


     /**
     * MD5 message digest provider.
     */
    protected static MessageDigest md5Helper;


    /**
     * The MD5 helper object for this class.
     */
    protected static final MD5Encoder md5Encoder = new MD5Encoder();



    static {
        creationDateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
    }


    // ----------------------------------------------------- Instance Variables


    /**
     * Repository of the locks put on single resources.
     * <p>
     * Key : path <br>
     * Value : LockInfo
     */
    private Hashtable resourceLocks = new Hashtable();


    /**
     * Repository of the lock-null resources.
     * <p>
     * Key : path of the collection containing the lock-null resource<br>
     * Value : Vector of lock-null resource which are members of the
     * collection. Each element of the Vector is the path associated with
     * the lock-null resource.
     */
    private Hashtable lockNullResources = new Hashtable();


    /**
     * Vector of the heritable locks.
     * <p>
     * Key : path <br>
     * Value : LockInfo
     */
    private Vector collectionLocks = new Vector();


    /**
     * Secret information used to generate reasonably secure lock ids.
     */
    private String secret = "catalina";


    // --------------------------------------------------------- Public Methods


    /**
     * Initialize this servlet.
     */
    public void init()
        throws ServletException {

        super.init();

        if (getServletConfig().getInitParameter("secret") != null)
            secret = getServletConfig().getInitParameter("secret");

        // Load the MD5 helper used to calculate signatures.
        try {
            md5Helper = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            throw new UnavailableException("No MD5");
        }

    }


    // ------------------------------------------------------ Protected Methods


    /**
     * Return JAXP document builder instance.
     */
    protected DocumentBuilder getDocumentBuilder()
        throws ServletException {
        DocumentBuilder documentBuilder = null;
        DocumentBuilderFactory documentBuilderFactory = null;
        try {
            documentBuilderFactory = DocumentBuilderFactory.newInstance();
            documentBuilderFactory.setNamespaceAware(true);
            documentBuilder = documentBuilderFactory.newDocumentBuilder();
        } catch(ParserConfigurationException e) {
            throw new ServletException
                (sm.getString("webdavservlet.jaxpfailed"));
        }
        return documentBuilder;
    }


    /**
     * Handles the special WebDAV methods.
     */
    protected void service(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

        String method = req.getMethod();

        if (debug > 0) {
            String path = getRelativePath(req);
            log("[" + method + "] " + path);
        }

        if (method.equals(METHOD_PROPFIND)) {
            doPropfind(req, resp);
        } else if (method.equals(METHOD_PROPPATCH)) {
            doProppatch(req, resp);
        } else if (method.equals(METHOD_MKCOL)) {
            doMkcol(req, resp);
        } else if (method.equals(METHOD_COPY)) {
            doCopy(req, resp);
        } else if (method.equals(METHOD_MOVE)) {
            doMove(req, resp);
        } else if (method.equals(METHOD_LOCK)) {
            doLock(req, resp);
        } else if (method.equals(METHOD_UNLOCK)) {
            doUnlock(req, resp);
        } else {
            // DefaultServlet processing
            super.service(req, resp);
        }

    }


    /**
     * Check if the conditions specified in the optional If headers are
     * satisfied.
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     * @param resourceAttributes The resource information
     * @return boolean true if the resource meets all the specified conditions,
     * and false if any of the conditions is not satisfied, in which case
     * request processing is stopped
     */
    protected boolean checkIfHeaders(HttpServletRequest request,
                                     HttpServletResponse response,
                                     ResourceAttributes resourceAttributes)
        throws IOException {

        if (!super.checkIfHeaders(request, response, resourceAttributes))
            return false;

        // TODO : Checking the WebDAV If header
        return true;

    }


    /**
     * OPTIONS Method.
     *
     * @param req The request
     * @param resp The response
     * @throws ServletException If an error occurs
     * @throws IOException If an IO error occurs
     */
    protected void doOptions(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

        resp.addHeader("DAV", "1,2");

        StringBuffer methodsAllowed = determineMethodsAllowed(resources,
                                                              req);

        resp.addHeader("Allow", methodsAllowed.toString());
        resp.addHeader("MS-Author-Via", "DAV");

    }


    /**
     * PROPFIND Method.
     */
    protected void doPropfind(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

        if (!listings) {
            // Get allowed methods
            StringBuffer methodsAllowed = determineMethodsAllowed(resources,
                                                                  req);

            resp.addHeader("Allow", methodsAllowed.toString());
            resp.sendError(WebdavStatus.SC_METHOD_NOT_ALLOWED);
            return;
        }

        String path = getRelativePath(req);
        if (path.endsWith("/"))
            path = path.substring(0, path.length() - 1);

        if ((path.toUpperCase().startsWith("/WEB-INF")) ||
            (path.toUpperCase().startsWith("/META-INF"))) {
            resp.sendError(WebdavStatus.SC_FORBIDDEN);
            return;
        }

        // Properties which are to be displayed.
        Vector properties = null;
        // Propfind depth
        int depth = INFINITY;
        // Propfind type
        int type = FIND_ALL_PROP;

        String depthStr = req.getHeader("Depth");

        if (depthStr == null) {
            depth = INFINITY;
        } else {
            if (depthStr.equals("0")) {
                depth = 0;
            } else if (depthStr.equals("1")) {
                depth = 1;
            } else if (depthStr.equals("infinity")) {
                depth = INFINITY;
            }
        }

        Node propNode = null;

        DocumentBuilder documentBuilder = getDocumentBuilder();

        try {
            Document document = documentBuilder.parse
                (new InputSource(req.getInputStream()));

            // Get the root element of the document
            Element rootElement = document.getDocumentElement();