2 * Copyright 2005-2011 the original author or authors.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 package org.wamblee.xmlrouter.impl;
18 import java.util.ArrayList;
19 import java.util.Collection;
20 import java.util.HashSet;
21 import java.util.LinkedHashMap;
22 import java.util.List;
25 import java.util.concurrent.atomic.AtomicLong;
26 import java.util.logging.Level;
27 import java.util.logging.Logger;
29 import javax.xml.transform.dom.DOMSource;
31 import org.wamblee.general.Clock;
32 import org.wamblee.xml.XMLDocument;
33 import org.wamblee.xmlrouter.common.Id;
34 import org.wamblee.xmlrouter.config.DocumentType;
35 import org.wamblee.xmlrouter.config.Filter;
36 import org.wamblee.xmlrouter.config.Transformation;
37 import org.wamblee.xmlrouter.listener.EventInfo;
38 import org.wamblee.xmlrouter.listener.EventListener;
39 import org.wamblee.xmlrouter.publish.Gateway;
40 import org.wamblee.xmlrouter.subscribe.Destination;
41 import org.wamblee.xmlrouter.subscribe.DestinationRegistry;
46 * @author Erik Brakkee
49 public class XMLRouter implements Gateway, DestinationRegistry {
51 private static final Logger LOGGER = Logger.getLogger(XMLRouter.class
54 private AtomicLong sequenceNumbers;
55 private EventListener listener;
57 private AtomicLong nextEventId;
59 private ExtendedRouterConfig routerConfig;
60 private TransformationPaths transformations;
62 private Map<Id<Destination>, Destination> destinations;
64 public XMLRouter(Clock aClock, ExtendedRouterConfig aRouterConfig,
65 EventListener aListener) {
66 sequenceNumbers = new AtomicLong(1);
69 nextEventId = new AtomicLong(clock.currentTimeMillis());
70 routerConfig = aRouterConfig;
71 transformations = new TransformationPaths();
72 destinations = new LinkedHashMap<Id<Destination>, Destination>();
76 public void publish(String aSource, DOMSource aEvent) {
77 long time = clock.currentTimeMillis();
79 if (routerConfig.isDirty()) {
80 transformations.replaceTransformations(routerConfig
81 .transformationConfig().map());
82 routerConfig.resetDirty();
85 Id<DOMSource> id = new Id<DOMSource>(nextEventId.getAndIncrement());
86 List<String> types = determineDocumentTypes(aEvent);
87 EventInfo info = new EventInfo(time, aSource, id, types, aEvent);
89 boolean delivered = false;
92 List<String> filteredInputTypes = determineFilteredInputTypes(
94 if (filteredInputTypes.isEmpty()) {
95 if (LOGGER.isLoggable(Level.FINE)) {
96 String doc = new XMLDocument(aEvent).print(true);
100 "Event ''0}'' from source {1} removed because of filters.",
101 new Object[] { doc, aSource });
105 // get the reachable target types through transformations.
107 // It is possible that a given event belongs to multiple input
109 // This is however certainly not the main case.
111 for (String inputType : filteredInputTypes) {
112 boolean result = deliverEvent(info, inputType);
113 delivered = delivered || result;
117 destinationNotFound(aSource, aEvent);
118 listener.notDelivered(info);
123 private boolean deliverEvent(EventInfo aInfo, String aInputType) {
125 boolean delivered = false;
126 Set<String> possibleTargetTypes = new HashSet<String>();
127 possibleTargetTypes.addAll(transformations
128 .getPossibleTargetTypes(aInputType));
130 // ask each destination what target types, if any they want to have.
131 for (Map.Entry<Id<Destination>, Destination> entry : destinations
133 Id<Destination> destinationId = entry.getKey();
134 Destination destination = entry.getValue();
135 Collection<String> requested = destination
136 .chooseFromTargetTypes(possibleTargetTypes);
137 if (!requested.isEmpty()) {
138 // Deliver to the destination.
139 for (String targetType : requested) {
140 TransformationPath path = transformations.getPath(
141 aInputType, targetType);
142 List<Transformation> ts = path.getTransformations();
144 boolean allowed = true;
145 DOMSource transformed = aInfo.getEvent();
146 while (i < ts.size() && allowed && transformed != null) {
147 Transformation t = ts.get(i);
148 DOMSource orig = transformed;
149 transformed = t.transform(transformed);
150 if (transformed == null) {
151 transformationReturnedNull(aInfo.getSource(),
152 aInfo.getEvent(), aInputType, t, orig);
155 if (!isAllowedByFilters(t.getToType(), transformed)) {
160 if (allowed && transformed != null) {
161 // all transformations done and all filters still
163 boolean result = destination.receive(transformed);
164 listener.delivered(aInfo, ts, destinationId.getId(),
165 destination.getName(), result);
166 delivered = delivered || result;
175 private List<String> determineFilteredInputTypes(List<String> aTypes,
178 // apply filters to the input
179 List<String> filteredTypes = new ArrayList<String>();
180 for (String type : aTypes) {
181 boolean allowed = isAllowedByFilters(type, aEvent);
183 filteredTypes.add(type);
186 return filteredTypes;
189 private boolean isAllowedByFilters(String aType, DOMSource aEvent) {
190 boolean allowed = true;
191 for (Filter filter : routerConfig.filterConfig().map().values()) {
192 if (!filter.isAllowed(aType, aEvent)) {
199 private List<String> determineDocumentTypes(DOMSource aEvent) {
200 List<String> res = new ArrayList<String>();
201 for (DocumentType type : routerConfig.documentTypeConfig().map()
203 if (type.isInstance(aEvent)) {
204 res.add(type.getName());
210 private void logEvent(String aMessage, String aSource, DOMSource aEvent) {
211 LOGGER.log(Level.WARNING,
212 aMessage + ": " + eventToString(aSource, aEvent));
215 private String eventToString(String aSource, DOMSource aEvent) {
216 return "source '" + aSource + "': Event: '" +
217 new XMLDocument(aEvent).print(true) + "'";
220 private void transformationReturnedNull(String aSource, DOMSource aEvent,
221 String aInputType, Transformation aT, DOMSource aTransformed) {
222 LOGGER.log(Level.WARNING, "Transformation returned null for event " +
223 eventToString(aSource, aEvent) + " inputType '" + aInputType +
224 "', transformation '" + aT + "' document to transform " +
225 new XMLDocument(aTransformed).print(true));
228 private void destinationNotFound(String aSource, DOMSource aEvent) {
229 LOGGER.log(Level.WARNING, "No destination found for event: " +
230 eventToString(aSource, aEvent));
234 public Id<Destination> registerDestination(Destination aDestination) {
235 notNull("destination", aDestination);
236 long seqno = sequenceNumbers.getAndIncrement();
237 Id<Destination> id = new Id<Destination>(seqno);
238 destinations.put(id, new RobustDestination(id, aDestination));
243 public void unregisterDestination(Id<Destination> aId) {
244 destinations.remove(aId);
247 private void notNull(String aName, Object aValue) {
248 if (aValue == null) {
249 throw new IllegalArgumentException("Parameter '" + aName +
250 "' may not be null");