/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.cxf.jaxrs.sse.atmosphere;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.lang.annotation.Annotation;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionStage;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.logging.Logger;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.sse.OutboundSseEvent;
import javax.ws.rs.sse.SseEventSink;
import org.apache.cxf.common.logging.LogUtils;
import org.atmosphere.cpr.AtmosphereResource;
import org.atmosphere.cpr.AtmosphereResponse;
import org.atmosphere.cpr.Broadcaster;
public class SseAtmosphereEventSinkImpl implements SseEventSink {
private static final Logger LOG = LogUtils.getL7dLogger(SseAtmosphereEventSinkImpl.class);
private final AtmosphereResource resource;
private final MessageBodyWriter<OutboundSseEvent> writer;
private volatile boolean closed;
public SseAtmosphereEventSinkImpl(final MessageBodyWriter<OutboundSseEvent> writer,
final AtmosphereResource resource) {
this.writer = writer;
this.resource = resource;
if (!resource.isSuspended()) {
LOG.fine("Atmosphere resource is not suspended, suspending");
resource.suspend();
}
}
@Override
public void close() {
if (!closed) {
closed = true;
LOG.fine("Closing Atmosphere SSE event output");
if (resource.isSuspended()) {
LOG.fine("Atmosphere resource is suspended, resuming");
resource.resume();
}
final Broadcaster broadcaster = resource.getBroadcaster();
resource.removeFromAllBroadcasters();
try {
final AtmosphereResponse response = resource.getResponse();
if (!response.isCommitted()) {
LOG.fine("Response is not committed, flushing buffer");
try {
response.flushBuffer();
} catch (IOException ex) {
//REVISIT: and throw a runtime exception ?
LOG.warning("Failed to flush AtmosphereResponse buffer");
}
}
response.closeStreamOrWriter();
} finally {
try {
resource.close();
} catch (IOException ex) {
// ignore
}
broadcaster.destroy();
LOG.fine("Atmosphere SSE event output is closed");
}
}
}
@Override
public CompletionStage<?> send(OutboundSseEvent event) {
final CompletableFuture<?> future = new CompletableFuture<>();
if (!closed && writer != null) {
try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
writer.writeTo(event, event.getClass(), null, new Annotation [] {}, event.getMediaType(), null, os);
// Atmosphere broadcasts asynchronously which is acceptable in most cases.
// Unfortunately, calling close() may lead to response stream being closed
// while there are still some SSE delivery scheduled.
return CompletableFuture.completedFuture(
resource
.getBroadcaster()
.broadcast(os.toString(StandardCharsets.UTF_8.name()))
.get(1, TimeUnit.SECONDS)
);
} catch (final IOException ex) {
LOG.warning("While writing the SSE event, an exception was raised: " + ex);
future.completeExceptionally(ex);
} catch (final ExecutionException | InterruptedException ex) {
LOG.warning("SSE Atmosphere response was not delivered");
future.completeExceptionally(ex);
} catch (final TimeoutException ex) {
LOG.warning("SSE Atmosphere response was not delivered within default timeout");
future.completeExceptionally(ex);
}
} else {
future.complete(null);
}
return future;
}
@Override
public boolean isClosed() {
return closed;
}
}