com.thinkberg.webdav.PropPatchHandler.java Source code

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Here is the source code for com.thinkberg.webdav.PropPatchHandler.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.AbstractDavResource;
import com.thinkberg.webdav.data.DavResource;
import com.thinkberg.webdav.data.DavResourceFactory;
import com.thinkberg.webdav.lock.LockException;
import com.thinkberg.webdav.lock.LockManager;
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.text.ParseException;
import java.util.ArrayList;
import java.util.List;

/**
 * Handle PROPPATCH requests. This will set, update or remove properties from a resource
 * or collection. Only works if the underlying VFS backend supports filesystem attributes.
 *
 * @author Matthias L. Jugel
 */
public class PropPatchHandler extends WebdavHandler {
    private static final Log LOG = LogFactory.getLog(PropPatchHandler.class);

    /**
     * Handle a PROPPATCH 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 {
        FileObject object = VFSBackend.resolveFile(request.getPathInfo());

        try {
            if (!LockManager.getInstance().evaluateCondition(object, getIf(request)).result) {
                response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
                return;
            }
        } catch (LockException e) {
            response.sendError(SC_LOCKED);
            return;
        } catch (ParseException e) {
            response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
            return;
        }

        if (object.exists()) {
            SAXReader saxReader = new SAXReader();
            try {
                Document propDoc = saxReader.read(request.getInputStream());
                logXml(propDoc);

                Element propUpdateEl = propDoc.getRootElement();
                List<Element> requestedProperties = new ArrayList<Element>();
                for (Object elObject : propUpdateEl.elements()) {
                    Element el = (Element) elObject;
                    String command = el.getName();
                    if (AbstractDavResource.TAG_PROP_SET.equals(command)
                            || AbstractDavResource.TAG_PROP_REMOVE.equals(command)) {
                        for (Object propElObject : el.elements()) {
                            for (Object propNameElObject : ((Element) propElObject).elements()) {
                                Element propNameEl = (Element) propNameElObject;
                                requestedProperties.add(propNameEl);
                            }
                        }
                    }
                }

                // respond as XML encoded multi status
                response.setContentType("text/xml");
                response.setCharacterEncoding("UTF-8");
                response.setStatus(SC_MULTI_STATUS);

                Document multiStatusResponse = getMultiStatusResponse(object, requestedProperties,
                        getBaseUrl(request));

                logXml(multiStatusResponse);

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

            } catch (DocumentException e) {
                LOG.error("invalid request: " + e.getMessage());
                response.sendError(HttpServletResponse.SC_BAD_REQUEST);
            }
        } else {
            LOG.error(object.getName().getPath() + " NOT FOUND");
            response.sendError(HttpServletResponse.SC_NOT_FOUND);
        }
    }

    /**
     * Get a multistatus response for each of the property set/remove requests.
     *
     * @param object              the context object the property requests apply to
     * @param requestedProperties the properties that should be set or removed
     * @param baseUrl             the base url of this server
     * @return an XML document that is the response
     * @throws FileSystemException if there is an error setting or removing a property
     */
    private Document getMultiStatusResponse(FileObject object, List<Element> requestedProperties, URL baseUrl)
            throws FileSystemException {
        Document propDoc = DocumentHelper.createDocument();
        propDoc.setXMLEncoding("UTF-8");

        Element multiStatus = propDoc.addElement(TAG_MULTISTATUS, NAMESPACE_DAV);
        Element responseEl = multiStatus.addElement(TAG_RESPONSE);
        try {
            URL url = new URL(baseUrl, URLEncoder.encode(object.getName().getPath(), "UTF-8"));
            responseEl.addElement(TAG_HREF).addText(url.toExternalForm());
        } catch (Exception e) {
            LOG.error("can't set HREF tag in response", e);
        }
        DavResource resource = DavResourceFactory.getInstance().getDavResource(object);
        resource.setPropertyValues(responseEl, requestedProperties);
        return propDoc;
    }
}