/** * * Copyright 2003-2007 Jive Software, 2016-2019 Florian Schmaus. * * 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.jivesoftware.smack; import java.util.ArrayDeque; import java.util.ArrayList; import java.util.List; import org.jivesoftware.smack.SmackException.NoResponseException; import org.jivesoftware.smack.SmackException.NotConnectedException; import org.jivesoftware.smack.XMPPException.XMPPErrorException; import org.jivesoftware.smack.filter.StanzaFilter; import org.jivesoftware.smack.packet.Stanza; /** * Provides a mechanism to collect Stanzas into a result queue that pass a * specified filter/matcher. The collector lets you perform blocking and polling * operations on the result queue. So, a StanzaCollector is more suitable to * use than a {@link StanzaListener} when you need to wait for a specific * result.
*
* Each stanza collector will queue up a configured number of packets for processing before
* older packets are automatically dropped. The default number is retrieved by
* {@link SmackConfiguration#getStanzaCollectorSize()}.
*
* @see XMPPConnection#createStanzaCollector(StanzaFilter)
* @author Matt Tucker
*/
public final class StanzaCollector implements AutoCloseable {
private final StanzaFilter packetFilter;
private final ArrayDeque type of the result stanza.
* @return the next stanza result, or P pollResult() {
return (P) resultQueue.poll();
}
/**
* Polls to see if a stanza is currently available and returns it, or
* immediately returns
* Throws an XMPPErrorException in case the polled stanzas did contain an XMPPError.
* type of the result stanza.
* @return the next available packet.
* @throws XMPPErrorException in case an error response.
*/
public P pollResultOrThrow() throws XMPPErrorException {
P result = pollResult();
if (result != null) {
XMPPErrorException.ifHasErrorThenThrow(result);
}
return result;
}
/**
* Returns the next available packet. The method call will block (not return) until a stanza is
* available.
*
* @param type of the result stanza.
* @return the next available packet.
* @throws InterruptedException if the calling thread was interrupted.
*/
@SuppressWarnings("unchecked")
// TODO: Consider removing this method as it is hardly ever useful.
public synchronized P nextResultBlockForever() throws InterruptedException {
throwIfCancelled();
while (true) {
P res = (P) resultQueue.poll();
if (res != null) {
return res;
}
if (cancelled) {
return null;
}
wait();
}
}
/**
* Returns the next available packet. The method call will block until the connection's default
* timeout has elapsed.
*
* @param type of the result stanza.
* @return the next available packet.
* @throws InterruptedException if the calling thread was interrupted.
*/
public P nextResult() throws InterruptedException {
return nextResult(connection.getReplyTimeout());
}
private volatile long waitStart;
/**
* Returns the next available stanza. The method call will block (not return) until a stanza is available or the
* type of the result stanza.
* @param timeout the timeout in milliseconds.
* @return the next available stanza or P nextResult(long timeout) throws InterruptedException {
throwIfCancelled();
P res = null;
long remainingWait = timeout;
waitStart = System.currentTimeMillis();
while (remainingWait > 0 && connectionException == null && !cancelled) {
synchronized (this) {
res = (P) resultQueue.poll();
if (res != null) {
return res;
}
wait(remainingWait);
}
remainingWait = timeout - (System.currentTimeMillis() - waitStart);
}
return res;
}
/**
* Returns the next available stanza. The method in equivalent to
* {@link #nextResultOrThrow(long)} where the timeout argument is the default reply timeout of
* the connection associated with this collector.
*
* @param type of the result stanza.
* @return the next available stanza.
* @throws XMPPErrorException in case an error response was received.
* @throws NoResponseException if there was no response from the server.
* @throws InterruptedException if the calling thread was interrupted.
* @throws NotConnectedException if the XMPP connection is not connected.
* @see #nextResultOrThrow(long)
*/
public P nextResultOrThrow() throws NoResponseException, XMPPErrorException,
InterruptedException, NotConnectedException {
return nextResultOrThrow(connection.getReplyTimeout());
}
/**
* Returns the next available stanza. The method call will block until a stanza is
* available or the
* Three things can happen when waiting for an response:
*
* in which this method will
*
* Additionally the method will throw a {@link NotConnectedException} if no response was
* received and the connection got disconnected.
* type of the result stanza.
* @return the next available stanza.
* @throws NoResponseException if there was no response from the server.
* @throws XMPPErrorException in case an error response was received.
* @throws InterruptedException if the calling thread was interrupted.
* @throws NotConnectedException if there was no response and the connection got disconnected.
*/
public P nextResultOrThrow(long timeout) throws NoResponseException,
XMPPErrorException, InterruptedException, NotConnectedException {
P result;
try {
result = nextResult(timeout);
} finally {
cancel();
}
if (result == null) {
if (connectionException != null) {
throw new NotConnectedException(connection, packetFilter, connectionException);
}
if (!connection.isConnected()) {
throw new NotConnectedException(connection, packetFilter);
}
throw NoResponseException.newWith(timeout, this, cancelled);
}
XMPPErrorException.ifHasErrorThenThrow(result);
return result;
}
private Listnull
, then
* all packets will match this collector.
*
* @param connection the connection the collector is tied to.
* @param configuration the configuration used to construct this collector
*/
StanzaCollector(XMPPConnection connection, Configuration configuration) {
this.connection = connection;
this.packetFilter = configuration.packetFilter;
this.resultQueue = new ArrayDeque<>(configuration.size);
this.maxQueueSize = configuration.size;
this.collectorToReset = configuration.collectorToReset;
this.request = configuration.request;
}
/**
* Explicitly cancels the stanza collector so that no more results are
* queued up. Once a stanza collector has been cancelled, it cannot be
* re-enabled. Instead, a new stanza collector must be created.
*/
public synchronized void cancel() {
// If the packet collector has already been cancelled, do nothing.
if (cancelled) {
return;
}
cancelled = true;
connection.removeStanzaCollector(this);
notifyAll();
if (collectorToReset != null) {
collectorToReset.cancel();
}
}
/**
* Returns the stanza filter associated with this stanza collector. The stanza
* filter is used to determine what stanzas are queued as results.
*
* @return the stanza filter.
*/
public StanzaFilter getStanzaFilter() {
return packetFilter;
}
/**
* Polls to see if a stanza is currently available and returns it, or
* immediately returns null
if no packets are currently in the
* result queue.
*
* @param null
if there are no more
* results.
*/
@SuppressWarnings("unchecked")
public synchronized null
if no packets are currently in the
* result queue.
* timeout
has elapsed or if the connection was terminated because of an error. If the timeout elapses without a
* result or if there was an connection error, null
will be returned.
*
* @param null
on timeout or connection error.
* @throws InterruptedException if the calling thread was interrupted.
*/
@SuppressWarnings("unchecked")
public timeout
has elapsed. This method does also cancel the
* collector in every case.
*
*
*
*
* null
, then all stanzas will
* get collected by this collector.
*
* @param stanzaFilter TODO javadoc me please
* @return a reference to this configuration.
*/
public Configuration setStanzaFilter(StanzaFilter stanzaFilter) {
this.packetFilter = stanzaFilter;
return this;
}
/**
* Set the maximum size of this collector, i.e. how many stanzas this collector will collect
* before dropping old ones.
*
* @param size TODO javadoc me please
* @return a reference to this configuration.
*/
public Configuration setSize(int size) {
this.size = size;
return this;
}
/**
* Set the collector which timeout for the next result is reset once this collector collects
* a packet.
*
* @param collector TODO javadoc me please
* @return a reference to this configuration.
*/
public Configuration setCollectorToReset(StanzaCollector collector) {
this.collectorToReset = collector;
return this;
}
public Configuration setRequest(Stanza request) {
this.request = request;
return this;
}
}
@Override
public void close() {
cancel();
}
}