/*****************************************************************
* 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.cayenne.remote;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.DataChannel;
import org.apache.cayenne.event.EventBridge;
import org.apache.cayenne.event.EventBridgeFactory;
import org.apache.cayenne.event.EventSubject;
import org.apache.cayenne.util.HashCodeBuilder;
import org.apache.cayenne.util.ToStringBuilder;
/**
* A descriptor used by default service implementation to pass session parameters to the
* client. It provides the client with details on how to invoke the service and how to
* listen for the server events.
*
* @since 1.2
*/
public class RemoteSession implements Serializable {
static final Collection<EventSubject> SUBJECTS = Arrays.asList(
DataChannel.GRAPH_CHANGED_SUBJECT,
DataChannel.GRAPH_FLUSHED_SUBJECT,
DataChannel.GRAPH_ROLLEDBACK_SUBJECT);
protected String name;
protected String sessionId;
protected String eventBridgeFactory;
protected Map eventBridgeParameters;
// private constructor used by hessian deserialization mechanism
@SuppressWarnings("unused")
private RemoteSession() {
}
/**
* Creates a HessianServiceDescriptor without server events support.
*/
public RemoteSession(String sessionId) {
this(sessionId, null, null);
}
/**
* Creates a HessianServiceDescriptor. If <code>eventBridgeFactory</code> argument
* is not null, session will support server events.
*/
public RemoteSession(String sessionId, String eventBridgeFactory,
Map eventBridgeParameters) {
if (sessionId == null) {
throw new IllegalArgumentException("Null sessionId");
}
this.sessionId = sessionId;
this.eventBridgeFactory = eventBridgeFactory;
this.eventBridgeParameters = eventBridgeParameters;
}
@Override
public int hashCode() {
return new HashCodeBuilder(71, 5).append(sessionId).toHashCode();
}
/**
* Returns server session id. This is often the same as HttpSession id.
*/
public String getSessionId() {
return sessionId;
}
/**
* Returns session group name. Group name is used for shared sessions.
*/
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isServerEventsEnabled() {
return eventBridgeFactory != null;
}
/**
* Creates an EventBridge that will listen for server events. Returns null if server
* events support is not configured in the descriptor.
*
* @throws CayenneRuntimeException if EventBridge startup fails for any reason.
*/
public EventBridge createServerEventBridge() throws CayenneRuntimeException {
if (!isServerEventsEnabled()) {
return null;
}
try {
EventBridgeFactory factory = (EventBridgeFactory) Class.forName(
eventBridgeFactory).newInstance();
Map parameters = eventBridgeParameters != null
? eventBridgeParameters
: Collections.EMPTY_MAP;
// must use "name", not the sessionId as an external subject for the event
// bridge
return factory.createEventBridge(SUBJECTS, name, parameters);
}
catch (Exception ex) {
throw new CayenneRuntimeException("Error creating EventBridge.", ex);
}
}
@Override
public String toString() {
ToStringBuilder builder = new ToStringBuilder(this)
.append("sessionId", sessionId);
if (eventBridgeFactory != null) {
builder.append("eventBridgeFactory", eventBridgeFactory);
}
if (name != null) {
builder.append("name", name);
}
return builder.toString();
}
}