org.objectstyle.cayenne.remote.hessian.HessianConnection Maven / Gradle / Ivy
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/* ====================================================================
*
* The ObjectStyle Group Software License, version 1.1
* ObjectStyle Group - http://objectstyle.org/
*
* Copyright (c) 2002-2005, Andrei (Andrus) Adamchik and individual authors
* of the software. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if any,
* must include the following acknowlegement:
* "This product includes software developed by independent contributors
* and hosted on ObjectStyle Group web site (http://objectstyle.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "ObjectStyle Group" and "Cayenne" must not be used to endorse
* or promote products derived from this software without prior written
* permission. For written permission, email
* "andrus at objectstyle dot org".
*
* 5. Products derived from this software may not be called "ObjectStyle"
* or "Cayenne", nor may "ObjectStyle" or "Cayenne" appear in their
* names without prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE OBJECTSTYLE GROUP OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals and hosted on ObjectStyle Group web site. For more
* information on the ObjectStyle Group, please see
* url is the
* only required parameter.
*/
public HessianConnection(String url, String userName, String password,
String sharedSessionName) {
if (url == null) {
throw new IllegalArgumentException("URL of Cayenne service is null.");
}
this.url = url;
this.userName = userName;
this.password = password;
this.sharedSessionName = sharedSessionName;
}
/**
* Returns a URL of Cayenne service used by this connector.
*/
public String getUrl() {
return url;
}
/**
* Returns user name that is used for basic authentication when connecting to the
* cayenne server.
*/
public String getUserName() {
return userName;
}
/**
* Returns password that is used for basic authentication when connecting to the
* cayenne server.
*/
public String getPassword() {
return password;
}
public String getSharedSessionName() {
return sharedSessionName;
}
public EventBridge getServerEventBridge() throws CayenneRuntimeException {
if (session == null) {
connect();
}
return session.isServerEventsEnabled() ? session.createServerEventBridge() : null;
}
/**
* Retunrs internal RemoteSession instance.
*/
RemoteSession getSession() {
return session;
}
/**
* Establishes server session if needed.
*/
protected void beforeSendMessage(ClientMessage message)
throws CayenneRuntimeException {
// for now only support session-based communications...
if (session == null) {
connect();
}
}
/**
* Sends a message to remote Cayenne Hessian service.
*/
protected Object doSendMessage(ClientMessage message) throws CayenneRuntimeException {
try {
return service.processMessage(message);
}
catch (Throwable th) {
th = unwindThrowable(th);
String errorMessage = buildExceptionMessage("Remote error", th);
throw new CayenneRuntimeException(errorMessage, th);
}
}
/**
* Establishes a session with remote service.
*/
protected synchronized void connect() throws CayenneRuntimeException {
if (session != null) {
return;
}
long t0 = 0;
if (logger.isInfoEnabled()) {
t0 = System.currentTimeMillis();
StringBuffer log = new StringBuffer("Connecting to [");
if (userName != null) {
log.append(userName);
if (password != null) {
log.append(":*******");
}
log.append("@");
}
log.append(url);
log.append("]");
if (sharedSessionName != null) {
log.append(" - shared session '").append(sharedSessionName).append("'");
}
else {
log.append(" - dedicated session.");
}
logger.info(log.toString());
}
// init service proxy...
HessianProxyFactory factory = new HessianProxyFactory(this);
factory.setSerializerFactory(HessianConfig.createFactory(
CLIENT_SERIALIZER_FACTORIES,
null));
factory.setUser(userName);
factory.setPassword(password);
try {
this.service = (RemoteService) factory.create(RemoteService.class, url);
}
catch (Throwable th) {
th = unwindThrowable(th);
String message = buildExceptionMessage("URL error", th);
throw new CayenneRuntimeException(message, th);
}
// create server session...
try {
session = (sharedSessionName != null) ? service
.establishSharedSession(sharedSessionName) : service
.establishSession();
if (logger.isInfoEnabled()) {
long time = System.currentTimeMillis() - t0;
logger.info("=== Connected, session: "
+ session
+ " - took "
+ time
+ " ms.");
}
}
catch (Throwable th) {
th = unwindThrowable(th);
th.printStackTrace();
String message = buildExceptionMessage(
"Error establishing remote session",
th);
throw new CayenneRuntimeException(message, th);
}
// TODO: send a connect event...
}
String buildExceptionMessage(String message, Throwable th) {
StringBuffer buffer = new StringBuffer(message);
buffer.append(". URL - ").append(url);
String thMessage = th.getMessage();
if (!Util.isEmptyString(thMessage)) {
buffer.append("; CAUSE - ").append(thMessage);
}
return buffer.toString();
}
/**
* Utility method to get exception cause. Implements special handling of Hessian
* exceptions.
*/
Throwable unwindThrowable(Throwable th) {
if (th instanceof HessianProtocolException) {
Throwable cause = ((HessianProtocolException) th).getRootCause();
if (cause != null) {
return unwindThrowable(cause);
}
}
else if (th instanceof HessianRuntimeException) {
Throwable cause = ((HessianRuntimeException) th).getRootCause();
if (cause != null) {
return unwindThrowable(cause);
}
}
return Util.unwindException(th);
}
}