/*
* Copyright (c) 2008-2017 the original author or authors.
*
* 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 org.cometd.annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicBoolean;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.inject.Inject;
import org.cometd.bayeux.Channel;
import org.cometd.bayeux.ChannelId;
import org.cometd.bayeux.MarkedReference;
import org.cometd.bayeux.Message;
import org.cometd.bayeux.client.ClientSessionChannel;
import org.cometd.bayeux.server.BayeuxServer;
import org.cometd.bayeux.server.ConfigurableServerChannel;
import org.cometd.bayeux.server.ConfigurableServerChannel.Initializer;
import org.cometd.bayeux.server.LocalSession;
import org.cometd.bayeux.server.ServerChannel;
import org.cometd.bayeux.server.ServerMessage;
import org.cometd.bayeux.server.ServerSession;
/**
* <p>Processes annotations in server-side service objects.</p>
* <p>Service objects must be annotated with {@link Service} at class level to be processed by this processor,
* for example:</p>
* <pre>
* @Service
* public class MyService
* {
* @Session
* private ServerSession session;
*
* @Configure("/foo")
* public void configureFoo(ConfigurableServerChannel channel)
* {
* channel.setPersistent(...);
* channel.addListener(...);
* channel.addAuthorizer(...);
* }
*
* @Listener("/foo")
* public void handleFooMessages(ServerSession remote, ServerMessage.Mutable message)
* {
* // Do something
* }
* }
* </pre>
* <p>The processor is used in this way:</p>
* <pre>
* BayeuxServer bayeux = ...;
* ServerAnnotationProcessor processor = ServerAnnotationProcessor.get(bayeux);
* MyService s = new MyService();
* processor.process(s);
* </pre>
*
* @see ClientAnnotationProcessor
*/
public class ServerAnnotationProcessor extends AnnotationProcessor {
private final ConcurrentMap<Object, LocalSession> sessions = new ConcurrentHashMap<>();
private final ConcurrentMap<Object, List<ListenerCallback>> listeners = new ConcurrentHashMap<>();
private final ConcurrentMap<Object, List<SubscriptionCallback>> subscribers = new ConcurrentHashMap<>();
private final ConcurrentMap<Object, List<RemoteCallCallback>> remoteCalls = new ConcurrentHashMap<>();
private final BayeuxServer bayeuxServer;
private final Object[] injectables;
public ServerAnnotationProcessor(BayeuxServer bayeuxServer) {
this(bayeuxServer, new Object[0]);
}
public ServerAnnotationProcessor(BayeuxServer bayeuxServer, Object... injectables) {
this.bayeuxServer = bayeuxServer;
this.injectables = injectables;
}
/**
* Processes dependencies annotated with {@link Inject} and {@link Session},
* configuration methods annotated with {@link Configure}, callback methods
* annotated with {@link Listener}, {@link Subscription} and {@link RemoteCall},
* and lifecycle methods annotated with {@link PostConstruct}.
*
* @param bean the annotated service instance
* @return true if the bean contains at least one annotation that has been processed, false otherwise
*/
public boolean process(Object bean) {
boolean result = processDependencies(bean);
result |= processConfigurations(bean);
result |= processCallbacks(bean);
result |= processPostConstruct(bean);
return result;
}
/**
* Processes the methods annotated with {@link Configure}.
*
* @param bean the annotated service instance
* @return true if at least one annotated configure has been processed, false otherwise
*/
public boolean processConfigurations(final Object bean) {
if (bean == null) {
return false;
}
Class<?> klass = bean.getClass();
Service serviceAnnotation = klass.getAnnotation(Service.class);
if (serviceAnnotation == null) {
return false;
}
List<Method> methods = findAnnotatedMethods(bean, Configure.class);
if (methods.isEmpty()) {
return false;
}
for (final Method method : methods) {
Configure configure = method.getAnnotation(Configure.class);
String[] channels = configure.value();
for (String channel : channels) {
final Initializer init = new Initializer() {
@Override
public void configureChannel(ConfigurableServerChannel channel) {
if (logger.isDebugEnabled()) {
logger.debug("Configure channel {} with method {} on bean {}", channel, method, bean);
}
invokePrivate(bean, method, channel);
}
};
MarkedReference<ServerChannel> initializedChannel = bayeuxServer.createChannelIfAbsent(channel, init);
if (!initializedChannel.isMarked()) {
if (configure.configureIfExists()) {
if (logger.isDebugEnabled()) {
logger.debug("Configure again channel {} with method {} on bean {}", channel, method, bean);
}
init.configureChannel(initializedChannel.getReference());
} else if (configure.errorIfExists()) {
throw new IllegalStateException("Channel already configured: " + channel);
} else {
if (logger.isDebugEnabled()) {
logger.debug("Channel {} already initialized. Not called method {} on bean {}", channel, method, bean);
}
}
}
}
}
return true;
}
/**
* Processes the dependencies annotated with {@link Inject} and {@link Session}.
*
* @param bean the annotated service instance
* @return true if at least one annotated dependency has been processed, false otherwise
*/
public boolean processDependencies(Object bean) {
if (bean == null) {
return false;
}
Class<?> klass = bean.getClass();
Service serviceAnnotation = klass.getAnnotation(Service.class);
if (serviceAnnotation == null) {
return false;
}
List<Object> injectables = new ArrayList<>(Arrays.asList(this.injectables));
injectables.add(0, bayeuxServer);
boolean result = processInjectables(bean, injectables);
LocalSession session = findOrCreateLocalSession(bean, serviceAnnotation.value());
result |= processSession(bean, session);
return result;
}
/**
* Processes lifecycle methods annotated with {@link PostConstruct}.
*
* @param bean the annotated service instance
* @return true if at least one lifecycle method has been invoked, false otherwise
*/
@Override
public boolean processPostConstruct(Object bean) {
return super.processPostConstruct(bean);
}
/**
* Processes the callbacks annotated with {@link Listener}, {@link Subscription}
* and {@link RemoteCall}.
*
* @param bean the annotated service instance
* @return true if at least one annotated callback has been processed, false otherwise
*/
public boolean processCallbacks(Object bean) {
if (bean == null) {
return false;
}
Class<?> klass = bean.getClass();
Service serviceAnnotation = klass.getAnnotation(Service.class);
if (serviceAnnotation == null) {
return false;
}
if (!Modifier.isPublic(klass.getModifiers())) {
throw new IllegalArgumentException("Service class " + klass.getName() + " must be public");
}
LocalSession session = findOrCreateLocalSession(bean, serviceAnnotation.value());
boolean result = processListener(bean, session);
result |= processSubscription(bean, session);
result |= processRemoteCall(bean, session);
return result;
}
/**
* Performs the opposite processing done by {@link #process(Object)} on callbacks methods
* annotated with {@link Listener}, {@link Subscription} and {@link RemoteCall}, and on
* lifecycle methods annotated with {@link PreDestroy}.
*
* @param bean the annotated service instance
* @return true if at least one deprocessing has been performed, false otherwise
* @see #process(Object)
*/
public boolean deprocess(Object bean) {
boolean result = deprocessCallbacks(bean);
result |= processPreDestroy(bean);
return result;
}
/**
* Performs the opposite processing done by {@link #processCallbacks(Object)} on callback methods
* annotated with {@link Listener}, {@link Subscription} and {@link RemoteCall}.
*
* @param bean the annotated service instance
* @return true if the at least one callback has been deprocessed
*/
public boolean deprocessCallbacks(Object bean) {
if (bean == null) {
return false;
}
Class<?> klass = bean.getClass();
Service serviceAnnotation = klass.getAnnotation(Service.class);
if (serviceAnnotation == null) {
return false;
}
boolean result = deprocessListener(bean);
result |= deprocessSubscription(bean);
result |= deprocessRemoteCall(bean);
destroyLocalSession(bean);
return result;
}
private void destroyLocalSession(Object bean) {
LocalSession session = sessions.remove(bean);
if (session != null) {
session.disconnect();
}
}
/**
* Processes lifecycle methods annotated with {@link PreDestroy}.
*
* @param bean the annotated service instance
* @return true if at least one lifecycle method has been invoked, false otherwise
*/
@Override
public boolean processPreDestroy(Object bean) {
return super.processPreDestroy(bean);
}
private LocalSession findOrCreateLocalSession(Object bean, String name) {
LocalSession session = sessions.get(bean);
if (session == null) {
session = bayeuxServer.newLocalSession(name);
LocalSession existing = sessions.putIfAbsent(bean, session);
if (existing != null) {
session = existing;
} else {
session.handshake();
}
}
return session;
}
private boolean processSession(Object bean, LocalSession localSession) {
ServerSession serverSession = localSession.getServerSession();
boolean result = false;
for (Class<?> c = bean.getClass(); c != Object.class; c = c.getSuperclass()) {
Field[] fields = c.getDeclaredFields();
for (Field field : fields) {
if (field.getAnnotation(Session.class) != null) {
Object value = null;
if (field.getType().isAssignableFrom(localSession.getClass())) {
value = localSession;
} else if (field.getType().isAssignableFrom(serverSession.getClass())) {
value = serverSession;
}
if (value != null) {
setField(bean, field, value);
result = true;
if (logger.isDebugEnabled()) {
logger.debug("Injected {} to field {} on bean {}", value, field, bean);
}
}
}
}
}
List<Method> methods = findAnnotatedMethods(bean, Session.class);
for (Method method : methods) {
Class<?>[] parameterTypes = method.getParameterTypes();
if (parameterTypes.length == 1) {
Object value = null;
if (parameterTypes[0].isAssignableFrom(localSession.getClass())) {
value = localSession;
} else if (parameterTypes[0].isAssignableFrom(serverSession.getClass())) {
value = serverSession;
}
if (value != null) {
invokePrivate(bean, method, value);
result = true;
if (logger.isDebugEnabled()) {
logger.debug("Injected {} to method {} on bean {}", value, method, bean);
}
}
}
}
return result;
}
private boolean processListener(Object bean, LocalSession localSession) {
checkMethodsPublic(bean, Listener.class);
boolean result = false;
Method[] methods = bean.getClass().getMethods();
for (Method method : methods) {
if (method.getDeclaringClass() == Object.class) {
continue;
}
Listener listener = method.getAnnotation(Listener.class);
if (listener != null) {
List<String> paramNames = processParameters(method);
checkSignaturesMatch(method, ListenerCallback.signature, paramNames);
String[] channels = listener.value();
for (String channel : channels) {
ChannelId channelId = new ChannelId(channel);
if (channelId.isTemplate()) {
List<String> parameters = channelId.getParameters();
if (parameters.size() != paramNames.size()) {
throw new IllegalArgumentException("Wrong number of template parameters in annotation @" +
Listener.class.getSimpleName() + " on method " +
method.getDeclaringClass().getName() + "." + method.getName() + "(...)");
}
if (!parameters.equals(paramNames)) {
throw new IllegalArgumentException("Wrong parameter names in annotation @" +
Listener.class.getSimpleName() + " on method " +
method.getDeclaringClass().getName() + "." + method.getName() + "(...)");
}
channel = channelId.getRegularPart() + "/" + (parameters.size() < 2 ? ChannelId.WILD : ChannelId.DEEPWILD);
}
MarkedReference<ServerChannel> initializedChannel = bayeuxServer.createChannelIfAbsent(channel);
ListenerCallback listenerCallback = new ListenerCallback(localSession, bean, method, paramNames, channelId, channel, listener.receiveOwnPublishes());
initializedChannel.getReference().addListener(listenerCallback);
List<ListenerCallback> callbacks = listeners.get(bean);
if (callbacks == null) {
callbacks = new CopyOnWriteArrayList<>();
List<ListenerCallback> existing = listeners.putIfAbsent(bean, callbacks);
if (existing != null) {
callbacks = existing;
}
}
callbacks.add(listenerCallback);
result = true;
if (logger.isDebugEnabled()) {
logger.debug("Registered listener for channel {} to method {} on bean {}", channel, method, bean);
}
}
}
}
return result;
}
private boolean deprocessListener(Object bean) {
boolean result = false;
List<ListenerCallback> callbacks = listeners.remove(bean);
if (callbacks != null) {
for (ListenerCallback callback : callbacks) {
ServerChannel channel = bayeuxServer.getChannel(callback.subscription);
if (channel != null) {
channel.removeListener(callback);
result = true;
}
}
}
return result;
}
private boolean processSubscription(Object bean, LocalSession localSession) {
checkMethodsPublic(bean, Subscription.class);
boolean result = false;
Method[] methods = bean.getClass().getMethods();
for (Method method : methods) {
if (method.getDeclaringClass() == Object.class) {
continue;
}
Subscription subscription = method.getAnnotation(Subscription.class);
if (subscription != null) {
List<String> paramNames = processParameters(method);
checkSignaturesMatch(method, SubscriptionCallback.signature, paramNames);
String[] channels = subscription.value();
for (String channel : channels) {
if (ChannelId.isMeta(channel)) {
throw new IllegalArgumentException("Annotation @" + Subscription.class.getSimpleName() +
" on method " + method.getDeclaringClass().getName() + "." + method.getName() +
"(...) must specify a non meta channel");
}
ChannelId channelId = new ChannelId(channel);
if (channelId.isTemplate()) {
List<String> parameters = channelId.getParameters();
if (parameters.size() != paramNames.size()) {
throw new IllegalArgumentException("Wrong number of template parameters in annotation @" +
Subscription.class.getSimpleName() + " on method " +
method.getDeclaringClass().getName() + "." + method.getName() + "(...)");
}
if (!parameters.equals(paramNames)) {
throw new IllegalArgumentException("Wrong parameter names in annotation @" +
Subscription.class.getSimpleName() + " on method " +
method.getDeclaringClass().getName() + "." + method.getName() + "(...)");
}
channel = channelId.getRegularPart() + "/" + (parameters.size() < 2 ? ChannelId.WILD : ChannelId.DEEPWILD);
}
SubscriptionCallback subscriptionCallback = new SubscriptionCallback(localSession, bean, method, paramNames, channelId, channel);
localSession.getChannel(channel).subscribe(subscriptionCallback);
List<SubscriptionCallback> callbacks = subscribers.get(bean);
if (callbacks == null) {
callbacks = new CopyOnWriteArrayList<>();
List<SubscriptionCallback> existing = subscribers.putIfAbsent(bean, callbacks);
if (existing != null) {
callbacks = existing;
}
}
callbacks.add(subscriptionCallback);
result = true;
if (logger.isDebugEnabled()) {
logger.debug("Registered subscriber for channel {} to method {} on bean {}", channel, method, bean);
}
}
}
}
return result;
}
private boolean deprocessSubscription(Object bean) {
boolean result = false;
List<SubscriptionCallback> callbacks = subscribers.remove(bean);
if (callbacks != null) {
for (SubscriptionCallback callback : callbacks) {
callback.localSession.getChannel(callback.subscription).unsubscribe(callback);
result = true;
}
}
return result;
}
private boolean processRemoteCall(Object bean, LocalSession localSession) {
checkMethodsPublic(bean, RemoteCall.class);
boolean result = false;
Method[] methods = bean.getClass().getMethods();
for (Method method : methods) {
RemoteCall remoteCall = method.getAnnotation(RemoteCall.class);
if (remoteCall != null) {
List<String> paramNames = processParameters(method);
checkSignaturesMatch(method, RemoteCallCallback.signature, paramNames);
String[] targets = remoteCall.value();
for (String target : targets) {
if (!target.startsWith("/")) {
target = "/" + target;
}
String channel = Channel.SERVICE + target;
ChannelId channelId = new ChannelId(channel);
if (channelId.isWild()) {
throw new IllegalArgumentException("Annotation @" + RemoteCall.class.getSimpleName() +
" on method " + method.getDeclaringClass().getName() + "." + method.getName() +
"(...) cannot specify wild channels.");
}
if (channelId.isTemplate()) {
List<String> parameters = channelId.getParameters();
if (parameters.size() != paramNames.size()) {
throw new IllegalArgumentException("Wrong number of template parameters in annotation @" +
RemoteCall.class.getSimpleName() + " on method " +
method.getDeclaringClass().getName() + "." + method.getName() + "(...)");
}
if (!parameters.equals(paramNames)) {
throw new IllegalArgumentException("Wrong parameter names in annotation @" +
RemoteCall.class.getSimpleName() + " on method " +
method.getDeclaringClass().getName() + "." + method.getName() + "(...)");
}
channel = channelId.getRegularPart() + "/" + (parameters.size() < 2 ? ChannelId.WILD : ChannelId.DEEPWILD);
}
MarkedReference<ServerChannel> initializedChannel = bayeuxServer.createChannelIfAbsent(channel);
RemoteCallCallback remoteCallCallback = new RemoteCallCallback(bayeuxServer, localSession, bean, method, paramNames, channelId, channel);
initializedChannel.getReference().addListener(remoteCallCallback);
List<RemoteCallCallback> callbacks = remoteCalls.get(bean);
if (callbacks == null) {
callbacks = new CopyOnWriteArrayList<>();
List<RemoteCallCallback> existing = remoteCalls.putIfAbsent(bean, callbacks);
if (existing != null) {
callbacks = existing;
}
}
callbacks.add(remoteCallCallback);
result = true;
if (logger.isDebugEnabled()) {
logger.debug("Registered remote call for channel {} to method {} on bean {}", target, method, bean);
}
}
}
}
return result;
}
private boolean deprocessRemoteCall(Object bean) {
boolean result = false;
List<RemoteCallCallback> callbacks = remoteCalls.remove(bean);
if (callbacks != null) {
for (RemoteCallCallback callback : callbacks) {
ServerChannel channel = bayeuxServer.getChannel(callback.subscription);
if (channel != null) {
channel.removeListener(callback);
result = true;
}
}
}
return result;
}
private static class ListenerCallback implements ServerChannel.MessageListener {
private static final Class<?>[] signature = new Class<?>[]{ServerSession.class, ServerMessage.Mutable.class};
private final LocalSession localSession;
private final Object target;
private final Method method;
private final ChannelId channelId;
private final String subscription;
private final boolean receiveOwnPublishes;
private final List<String> paramNames;
private ListenerCallback(LocalSession localSession, Object target, Method method, List<String> paramNames, ChannelId channelId, String subscription, boolean receiveOwnPublishes) {
this.localSession = localSession;
this.target = target;
this.method = method;
this.paramNames = paramNames;
this.channelId = channelId;
this.subscription = subscription;
this.receiveOwnPublishes = receiveOwnPublishes;
}
@Override
public boolean onMessage(ServerSession from, ServerChannel channel, ServerMessage.Mutable message) {
if (from == localSession.getServerSession() && !receiveOwnPublishes) {
return true;
}
Map<String, String> matches = channelId.bind(channel.getChannelId());
if (!paramNames.isEmpty() && !matches.keySet().containsAll(paramNames)) {
return true;
}
Object[] args = new Object[2 + paramNames.size()];
args[0] = from;
args[1] = message;
for (int i = 0; i < paramNames.size(); ++i) {
args[2 + i] = matches.get(paramNames.get(i));
}
return !Boolean.FALSE.equals(invokePublic(target, method, args));
}
}
private static class SubscriptionCallback implements ClientSessionChannel.MessageListener {
private static final Class<?>[] signature = new Class<?>[]{Message.class};
private final LocalSession localSession;
private final Object target;
private final Method method;
private final List<String> paramNames;
private final ChannelId channelId;
private final String subscription;
public SubscriptionCallback(LocalSession localSession, Object target, Method method, List<String> paramNames, ChannelId channelId, String subscription) {
this.localSession = localSession;
this.target = target;
this.method = method;
this.paramNames = paramNames;
this.channelId = channelId;
this.subscription = subscription;
}
@Override
public void onMessage(ClientSessionChannel channel, Message message) {
Map<String, String> matches = channelId.bind(message.getChannelId());
if (!paramNames.isEmpty() && !matches.keySet().containsAll(paramNames)) {
return;
}
Object[] args = new Object[1 + paramNames.size()];
args[0] = message;
for (int i = 0; i < paramNames.size(); ++i) {
args[1 + i] = matches.get(paramNames.get(i));
}
invokePublic(target, method, args);
}
}
private static class RemoteCallCallback implements ServerChannel.MessageListener {
private static final Class<?>[] signature = new Class<?>[]{RemoteCall.Caller.class, null};
private final BayeuxServer bayeuxServer;
private final LocalSession localSession;
private final Object target;
private final Method method;
private final List<String> paramNames;
private final ChannelId channelId;
private final String subscription;
private RemoteCallCallback(BayeuxServer bayeuxServer, LocalSession localSession, Object target, Method method, List<String> paramNames, ChannelId channelId, String subscription) {
this.bayeuxServer = bayeuxServer;
this.localSession = localSession;
this.target = target;
this.method = method;
this.paramNames = paramNames;
this.channelId = channelId;
this.subscription = subscription;
}
@Override
public boolean onMessage(ServerSession from, ServerChannel channel, ServerMessage.Mutable message) {
// Protect against (wrong) publishes on the remote call channel.
if (from == localSession.getServerSession()) {
return true;
}
Map<String, String> matches = channelId.bind(channel.getChannelId());
if (!paramNames.isEmpty() && !matches.keySet().containsAll(paramNames)) {
return true;
}
Object[] args = new Object[2 + paramNames.size()];
RemoteCall.Caller caller = new CallerImpl(bayeuxServer, localSession, from, message.getId(), message.getChannel());
args[0] = caller;
args[1] = message.getData();
for (int i = 0; i < paramNames.size(); ++i) {
args[2 + i] = matches.get(paramNames.get(i));
}
try {
return !Boolean.FALSE.equals(invokePublic(target, method, args));
} catch (Throwable x) {
Map<String, Object> failure = new HashMap<>();
failure.put("class", x.getClass().getName());
failure.put("message", x.getMessage());
caller.failure(failure);
throw x;
}
}
}
private static class CallerImpl implements RemoteCall.Caller {
private final AtomicBoolean complete = new AtomicBoolean();
private final BayeuxServer bayeux;
private final LocalSession sender;
private final ServerSession session;
private final String messageId;
private final String channel;
private CallerImpl(BayeuxServer bayeux, LocalSession sender, ServerSession session, String messageId, String channel) {
this.bayeux = bayeux;
this.sender = sender;
this.session = session;
this.messageId = messageId;
this.channel = channel;
}
@Override
public ServerSession getServerSession() {
return session;
}
@Override
public boolean result(Object result) {
return deliver(result, true);
}
@Override
public boolean failure(Object failure) {
return deliver(failure, false);
}
private boolean deliver(Object data, boolean successful) {
boolean completed = complete.compareAndSet(false, true);
if (completed) {
ServerMessage.Mutable message = bayeux.newMessage();
message.setId(messageId);
message.setSuccessful(successful);
message.setChannel(channel);
message.setData(data);
session.deliver(sender, message);
}
return completed;
}
}
}