Examples with ElementImpl org.exist.dom.memtree.ElementImpl used on opensource projects

Example 16 with ElementImpl

use of org.exist.dom.memtree.ElementImpl in project exist by eXist-db.

the class RESTServer method doGet.

/**
 * Handle GET request. In the simplest case just returns the document or
 * binary resource specified in the path. If the path leads to a collection,
 * a listing of the collection contents is returned. If it resolves to a
 * binary resource with mime-type "application/xquery", this resource will
 * be loaded and executed by the XQuery engine.
 *
 * The method also recognizes a number of predefined parameters:
 *
 * <ul> <li>_xpath or _query: if specified, the given query is executed on
 * the current resource or collection.</li>
 *
 * <li>_howmany: defines how many items from the query result will be
 * returned.</li>
 *
 * <li>_start: a start offset into the result set.</li>
 *
 * <li>_wrap: if set to "yes", the query results will be wrapped into a
 * exist:result element.</li>
 *
 * <li>_indent: if set to "yes", the returned XML will be pretty-printed.
 * </li>
 *
 * <li>_source: if set to "yes" and a resource with mime-type
 * "application/xquery" is requested then the xquery will not be executed,
 * instead the source of the document will be returned. Must be enabled in
 * descriptor.xml with the following syntax
 * <pre>{@code
 *     <xquery-app>
 *         <allow-source>
 *             <xquery path="/db/mycollection/myquery.xql"/>
 *         </allow-source>
 *     </xquery-app>
 * }</pre>
 * </li>
 *
 * <li>_xsl: an URI pointing to an XSL stylesheet that will be applied to
 * the returned XML.</li>
 * </ul>
 *
 * @param broker the database broker
 * @param transaction the database transaction
 * @param request the request
 * @param response the response
 * @param path the path of the request
 *
 * @throws BadRequestException if a bad request is made
 * @throws PermissionDeniedException if the request has insufficient permissions
 * @throws NotFoundException if the request resource cannot be found
 * @throws IOException if an I/O error occurs
 */
public void doGet(final DBBroker broker, final Txn transaction, final HttpServletRequest request, final HttpServletResponse response, final String path) throws BadRequestException, PermissionDeniedException, NotFoundException, IOException {
    // if required, set character encoding
    if (request.getCharacterEncoding() == null) {
        request.setCharacterEncoding(formEncoding);
    }
    String option;
    if ((option = getParameter(request, Release)) != null) {
        final int sessionId = Integer.parseInt(option);
        sessionManager.release(sessionId);
        if (LOG.isDebugEnabled()) {
            LOG.debug("Released session {}", sessionId);
        }
        response.setStatus(HttpServletResponse.SC_OK);
        return;
    }
    // Process special parameters
    int howmany = 10;
    int start = 1;
    boolean typed = false;
    boolean wrap = true;
    boolean source = false;
    boolean cache = false;
    final Properties outputProperties = new Properties(defaultOutputKeysProperties);
    String query = null;
    if (!safeMode) {
        query = getParameter(request, XPath);
        if (query == null) {
            query = getParameter(request, Query);
        }
    }
    final String _var = getParameter(request, Variables);
    List /*<Namespace>*/
    namespaces = null;
    ElementImpl variables = null;
    try {
        if (_var != null) {
            final NamespaceExtractor nsExtractor = new NamespaceExtractor();
            variables = parseXML(broker.getBrokerPool(), _var, nsExtractor);
            namespaces = nsExtractor.getNamespaces();
        }
    } catch (final SAXException e) {
        final XPathException x = new XPathException(e.toString());
        writeXPathException(response, HttpServletResponse.SC_BAD_REQUEST, "UTF-8", query, path, x);
    }
    if ((option = getParameter(request, HowMany)) != null) {
        try {
            howmany = Integer.parseInt(option);
        } catch (final NumberFormatException nfe) {
            throw new BadRequestException("Parameter _howmany should be an int");
        }
    }
    if ((option = getParameter(request, Start)) != null) {
        try {
            start = Integer.parseInt(option);
        } catch (final NumberFormatException nfe) {
            throw new BadRequestException("Parameter _start should be an int");
        }
    }
    if ((option = getParameter(request, Typed)) != null) {
        if ("yes".equals(option.toLowerCase())) {
            typed = true;
        }
    }
    if ((option = getParameter(request, Wrap)) != null) {
        wrap = "yes".equals(option);
        outputProperties.setProperty("_wrap", option);
    }
    if ((option = getParameter(request, Cache)) != null) {
        cache = "yes".equals(option);
    }
    if ((option = getParameter(request, Indent)) != null) {
        outputProperties.setProperty(OutputKeys.INDENT, option);
    }
    if ((option = getParameter(request, Source)) != null && !safeMode) {
        source = "yes".equals(option);
    }
    if ((option = getParameter(request, Session)) != null) {
        outputProperties.setProperty(Serializer.PROPERTY_SESSION_ID, option);
    }
    String stylesheet;
    if ((stylesheet = getParameter(request, XSL)) != null) {
        if ("no".equals(stylesheet)) {
            outputProperties.setProperty(EXistOutputKeys.PROCESS_XSL_PI, "no");
            outputProperties.remove(EXistOutputKeys.STYLESHEET);
            stylesheet = null;
        } else {
            outputProperties.setProperty(EXistOutputKeys.STYLESHEET, stylesheet);
        }
    } else {
        outputProperties.setProperty(EXistOutputKeys.PROCESS_XSL_PI, "yes");
    }
    LOG.debug("stylesheet = {}", stylesheet);
    LOG.debug("query = {}", query);
    String encoding;
    if ((encoding = getParameter(request, Encoding)) != null) {
        outputProperties.setProperty(OutputKeys.ENCODING, encoding);
    } else {
        encoding = "UTF-8";
    }
    final String mimeType = outputProperties.getProperty(OutputKeys.MEDIA_TYPE);
    if (query != null) {
        // query parameter specified, search method does all the rest of the work
        try {
            search(broker, transaction, query, path, namespaces, variables, howmany, start, typed, outputProperties, wrap, cache, request, response);
        } catch (final XPathException e) {
            if (MimeType.XML_TYPE.getName().equals(mimeType)) {
                writeXPathException(response, HttpServletResponse.SC_BAD_REQUEST, encoding, query, path, e);
            } else {
                writeXPathExceptionHtml(response, HttpServletResponse.SC_BAD_REQUEST, encoding, query, path, e);
            }
        }
        return;
    }
    // Process the request
    LockedDocument lockedDocument = null;
    DocumentImpl resource = null;
    final XmldbURI pathUri = XmldbURI.createInternal(path);
    try {
        // check if path leads to an XQuery resource
        final String xquery_mime_type = MimeType.XQUERY_TYPE.getName();
        final String xproc_mime_type = MimeType.XPROC_TYPE.getName();
        lockedDocument = broker.getXMLResource(pathUri, LockMode.READ_LOCK);
        resource = lockedDocument == null ? null : lockedDocument.getDocument();
        if (null != resource && !isExecutableType(resource)) {
            // return regular resource that is not an xquery and not is xproc
            writeResourceAs(resource, broker, transaction, stylesheet, encoding, null, outputProperties, request, response);
            return;
        }
        if (resource == null) {
            // no document: check if path points to a collection
            try (final Collection collection = broker.openCollection(pathUri, LockMode.READ_LOCK)) {
                if (collection != null) {
                    if (safeMode || !collection.getPermissionsNoLock().validate(broker.getCurrentSubject(), Permission.READ)) {
                        throw new PermissionDeniedException("Not allowed to read collection");
                    }
                    // return a listing of the collection contents
                    try {
                        writeCollection(response, encoding, broker, collection);
                        return;
                    } catch (final LockException le) {
                        if (MimeType.XML_TYPE.getName().equals(mimeType)) {
                            writeXPathException(response, HttpServletResponse.SC_BAD_REQUEST, encoding, query, path, new XPathException(le.getMessage(), le));
                        } else {
                            writeXPathExceptionHtml(response, HttpServletResponse.SC_BAD_REQUEST, encoding, query, path, new XPathException(le.getMessage(), le));
                        }
                    }
                } else if (source) {
                    // on a possible xquery resource that was not found
                    throw new NotFoundException("Document " + path + " not found");
                }
            }
        }
        XmldbURI servletPath = pathUri;
        // xquery or xproc resource
        while (null == resource) {
            // traverse up the path looking for xquery objects
            servletPath = servletPath.removeLastSegment();
            if (servletPath == XmldbURI.EMPTY_URI) {
                break;
            }
            lockedDocument = broker.getXMLResource(servletPath, LockMode.READ_LOCK);
            resource = lockedDocument == null ? null : lockedDocument.getDocument();
            if (null != resource && isExecutableType(resource)) {
                break;
            } else if (null != resource) {
                // moving up the path, so bail out now
                throw new NotFoundException("Document " + path + " not found");
            }
        }
        if (null == resource) {
            // path search failed
            throw new NotFoundException("Document " + path + " not found");
        }
        // found an XQuery or XProc resource, fixup request values
        final String pathInfo = pathUri.trimFromBeginning(servletPath).toString();
        // Should we display the source of the XQuery or XProc or execute it
        final Descriptor descriptor = Descriptor.getDescriptorSingleton();
        if (source) {
            // descriptor.xml
            if ((null != descriptor) && descriptor.allowSource(path) && resource.getPermissions().validate(broker.getCurrentSubject(), Permission.READ)) {
                if (xquery_mime_type.equals(resource.getMimeType())) {
                    // Show the source of the XQuery
                    writeResourceAs(resource, broker, transaction, stylesheet, encoding, MimeType.TEXT_TYPE.getName(), outputProperties, request, response);
                } else if (xproc_mime_type.equals(resource.getMimeType())) {
                    // Show the source of the XProc
                    writeResourceAs(resource, broker, transaction, stylesheet, encoding, MimeType.XML_TYPE.getName(), outputProperties, request, response);
                }
            } else {
                // we are not allowed to show the source - query not
                // allowed in descriptor.xml
                // or descriptor not found, so assume source view not
                // allowed
                response.sendError(HttpServletResponse.SC_FORBIDDEN, "Permission to view XQuery source for: " + path + " denied. Must be explicitly defined in descriptor.xml");
                return;
            }
        } else {
            try {
                if (xquery_mime_type.equals(resource.getMimeType())) {
                    // Execute the XQuery
                    executeXQuery(broker, transaction, resource, request, response, outputProperties, servletPath.toString(), pathInfo);
                } else if (xproc_mime_type.equals(resource.getMimeType())) {
                    // Execute the XProc
                    executeXProc(broker, transaction, resource, request, response, outputProperties, servletPath.toString(), pathInfo);
                }
            } catch (final XPathException e) {
                if (LOG.isDebugEnabled()) {
                    LOG.debug(e.getMessage(), e);
                }
                if (MimeType.XML_TYPE.getName().equals(mimeType)) {
                    writeXPathException(response, HttpServletResponse.SC_BAD_REQUEST, encoding, query, path, e);
                } else {
                    writeXPathExceptionHtml(response, HttpServletResponse.SC_BAD_REQUEST, encoding, query, path, e);
                }
            }
        }
    } finally {
        if (lockedDocument != null) {
            lockedDocument.close();
        }
    }
}