/*
* Copyright 2000-2016 Vaadin Ltd.
*
* 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.vaadin.server;
import java.io.IOException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.servlet.http.HttpServletResponse;
import com.vaadin.shared.ApplicationConstants;
import com.vaadin.ui.LegacyComponent;
import com.vaadin.ui.UI;
import com.vaadin.util.CurrentInstance;
/**
* A {@link RequestHandler} that takes care of {@link ConnectorResource}s that
* should not be served by the connector.
*
* @author Vaadin Ltd
* @version @VERSION@
* @since 7.0.0
*/
public class GlobalResourceHandler implements RequestHandler {
private static final String LEGACY_TYPE = "legacy";
private static final String RESOURCE_REQUEST_PATH = "global/";
/**
* Used to detect when a resource is no longer used by any connector.
*/
private final Map<Resource, Set<ClientConnector>> resourceUsers = new HashMap<>();
/**
* Used to find the resources that might not be needed any more when a
* connector is unregistered.
*/
private final Map<ClientConnector, Set<Resource>> usedResources = new HashMap<>();
private final Map<ConnectorResource, String> legacyResourceKeys = new HashMap<>();
private final Map<String, ConnectorResource> legacyResources = new HashMap<>();
private int nextLegacyId = 0;
// APP/global/[uiid]/[type]/[id]
private static final Pattern pattern = Pattern
.compile("^/?" + ApplicationConstants.APP_PATH + '/'
+ RESOURCE_REQUEST_PATH + "(\\d+)/(([^/]+)(/.*))");
@Override
public boolean handleRequest(VaadinSession session, VaadinRequest request,
VaadinResponse response) throws IOException {
String pathInfo = request.getPathInfo();
if (pathInfo == null) {
return false;
}
Matcher matcher = pattern.matcher(pathInfo);
if (!matcher.matches()) {
return false;
}
String uiid = matcher.group(1);
String type = matcher.group(3);
String key = matcher.group(2);
if (key == null) {
return error(request, response,
pathInfo + " is not a valid global resource path");
}
session.lock();
Map<Class<?>, CurrentInstance> oldInstances = null;
DownloadStream stream = null;
try {
UI ui = session.getUIById(Integer.parseInt(uiid));
if (ui == null) {
return error(request, response, "No UI found for id " + uiid);
}
oldInstances = CurrentInstance.setCurrent(ui);
ConnectorResource resource;
if (LEGACY_TYPE.equals(type)) {
resource = legacyResources.get(key);
} else {
return error(request, response, "Unknown global resource type "
+ type + " in requested path " + pathInfo);
}
if (resource == null) {
return error(request, response,
"Global resource " + key + " not found");
}
stream = resource.getStream();
if (stream == null) {
return error(request, response,
"Resource " + resource + " didn't produce any stream.");
}
} finally {
session.unlock();
if (oldInstances != null) {
CurrentInstance.restoreInstances(oldInstances);
}
}
stream.writeResponse(request, response);
return true;
}
/**
* Registers a resource to be served with a global URL.
* <p>
* A {@link ConnectorResource} registered for a {@link LegacyComponent} will
* be set to be served with a global URL. Other resource types will be
* ignored and thus not served by this handler.
*
* @param resource
* the resource to register
* @param ownerConnector
* the connector to which the resource belongs
*/
public void register(Resource resource, ClientConnector ownerConnector) {
if (resource instanceof ConnectorResource) {
if (!(ownerConnector instanceof LegacyComponent)) {
throw new IllegalArgumentException(
"A normal ConnectorResource can only be registered for legacy components.");
}
ConnectorResource connectorResource = (ConnectorResource) resource;
if (!legacyResourceKeys.containsKey(resource)) {
String uri = LEGACY_TYPE + '/'
+ Integer.toString(nextLegacyId++);
String filename = connectorResource.getFilename();
if (filename != null && !filename.isEmpty()) {
uri += '/' + filename;
}
legacyResourceKeys.put(connectorResource, uri);
legacyResources.put(uri, connectorResource);
registerResourceUsage(connectorResource, ownerConnector);
}
}
}
private void unregisterResource(Resource resource) {
String oldUri = legacyResourceKeys.remove(resource);
if (oldUri != null) {
legacyResources.remove(oldUri);
}
}
private void registerResourceUsage(Resource resource,
ClientConnector connector) {
ensureInSet(resourceUsers, resource, connector);
ensureInSet(usedResources, connector, resource);
}
private <K, V> void ensureInSet(Map<K, Set<V>> map, K key, V value) {
Set<V> set = map.get(key);
if (set == null) {
set = new HashSet<>();
map.put(key, set);
}
set.add(value);
}
/**
* Gets a global URI for a resource if it's registered with this handler.
*
* @param connector
* the connector for which the uri should be generated.
* @param resource
* the resource for which the uri should be generated.
* @return an URI string, or <code>null</code> if the resource is not
* registered.
*/
public String getUri(ClientConnector connector,
ConnectorResource resource) {
// app://APP/global/[ui]/[type]/[id]
String uri = legacyResourceKeys.get(resource);
if (uri != null && !uri.isEmpty()) {
return ApplicationConstants.APP_PROTOCOL_PREFIX
+ ApplicationConstants.APP_PATH + '/'
+ RESOURCE_REQUEST_PATH + connector.getUI().getUIId() + '/'
+ uri;
} else {
return null;
}
}
/**
* Notifies this handler that resources registered for the given connector
* can be released.
*
* @param connector
* the connector for which any registered resources can be
* released.
*/
public void unregisterConnector(ClientConnector connector) {
Set<Resource> set = usedResources.remove(connector);
if (set == null) {
return;
}
for (Resource resource : set) {
Set<ClientConnector> users = resourceUsers.get(resource);
users.remove(connector);
if (users.isEmpty()) {
resourceUsers.remove(resource);
unregisterResource(resource);
}
}
}
private static Logger getLogger() {
return Logger.getLogger(GlobalResourceHandler.class.getName());
}
private static boolean error(VaadinRequest request, VaadinResponse response,
String logMessage) throws IOException {
getLogger().log(Level.WARNING, logMessage);
response.sendError(HttpServletResponse.SC_NOT_FOUND,
request.getPathInfo() + " can not be found");
// Request handled (though not in a nice way)
return true;
}
}