com.thinkberg.webdav.PropFindHandler.java Source code

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Here is the source code for com.thinkberg.webdav.PropFindHandler.java

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/*
 * Copyright 2007 Matthias L. Jugel.
 *
 * Licensed 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 com.thinkberg.webdav;

import com.thinkberg.webdav.data.DavResource;
import com.thinkberg.webdav.data.DavResourceFactory;
import com.thinkberg.webdav.vfs.DepthFileSelector;
import com.thinkberg.webdav.vfs.VFSBackend;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.vfs.FileObject;
import org.apache.commons.vfs.FileSystemException;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URL;
import java.util.Arrays;
import java.util.List;

/**
 * @author Matthias L. Jugel
 * @version $Id$
 */
public class PropFindHandler extends WebdavHandler {
    private static final Log LOG = LogFactory.getLog(PropFindHandler.class);

    // these tags are valid children elements of <propfind>
    private static final List<String> VALID_PROPFIND_TAGS = Arrays.asList(TAG_ALLPROP, TAG_PROPNAMES, TAG_PROP);

    /**
     * Handle a PROPFIND request.
     *
     * @param request  the servlet request
     * @param response the servlet response
     * @throws IOException if there is an error that cannot be handled normally
     */
    public void service(HttpServletRequest request, HttpServletResponse response) throws IOException {
        SAXReader saxReader = new SAXReader();
        try {
            Document propDoc = saxReader.read(request.getInputStream());
            logXml(propDoc);

            Element propFindEl = propDoc.getRootElement();
            for (Object propElObject : propFindEl.elements()) {
                Element propEl = (Element) propElObject;
                if (VALID_PROPFIND_TAGS.contains(propEl.getName())) {
                    FileObject object = VFSBackend.resolveFile(request.getPathInfo());
                    if (object.exists()) {
                        // respond as XML encoded multi status
                        response.setContentType("text/xml");
                        response.setCharacterEncoding("UTF-8");
                        response.setStatus(SC_MULTI_STATUS);

                        Document multiStatusResponse = getMultiStatusResponse(object, propEl, getBaseUrl(request),
                                getDepth(request));
                        logXml(multiStatusResponse);

                        // write the actual response
                        XMLWriter writer = new XMLWriter(response.getWriter(), OutputFormat.createCompactFormat());
                        writer.write(multiStatusResponse);
                        writer.flush();
                        writer.close();

                    } else {
                        response.sendError(HttpServletResponse.SC_NOT_FOUND);
                    }
                    break;
                }
            }
        } catch (DocumentException e) {
            LOG.error("invalid request: " + e.getMessage());
            response.sendError(HttpServletResponse.SC_BAD_REQUEST);
        }
    }

    /**
     * Create a multistatus response by requesting all properties and writing a response for each
     * the found and the non-found properties
     *
     * @param object  the context object the propfind request applies to
     * @param propEl  the &lt;prop&gt; element containing the actual properties
     * @param baseUrl the base url of this server
     * @param depth   a depth argument for how deep the find will go
     * @return an XML document that is the response
     * @throws FileSystemException if there was an error executing the propfind request
     */
    private Document getMultiStatusResponse(FileObject object, Element propEl, URL baseUrl, int depth)
            throws FileSystemException {
        Document propDoc = DocumentHelper.createDocument();
        propDoc.setXMLEncoding("UTF-8");

        Element multiStatus = propDoc.addElement(TAG_MULTISTATUS, NAMESPACE_DAV);
        FileObject[] children = object.findFiles(new DepthFileSelector(depth));
        for (FileObject child : children) {
            Element responseEl = multiStatus.addElement(TAG_RESPONSE);
            try {
                URL url = new URL(baseUrl, URLEncoder.encode(child.getName().getPath(), "UTF-8"));
                responseEl.addElement(TAG_HREF).addText(url.toExternalForm());
            } catch (Exception e) {
                LOG.error("can't set href in response", e);
            }
            DavResource resource = DavResourceFactory.getInstance().getDavResource(child);
            resource.getPropertyValues(responseEl, propEl);
        }
        return propDoc;
    }
}