com.sun.ejb.containers.EjbRemoteFutureTask Maven / Gradle / Ivy
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/*
* Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.ejb.containers;
import java.util.concurrent.Future;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.TimeUnit;
import java.rmi.RemoteException;
import java.io.Serializable;
import jakarta.ejb.EJBException;
/**
* @author Ken Saks
*/
public class EjbRemoteFutureTask
implements Future, Serializable {
private Long asyncId;
private GenericEJBHome server;
// Used to remember if cancel() was called already
private boolean cancelCalled = false;
private boolean complete = false;
private V resultValue;
private Throwable resultException;
public EjbRemoteFutureTask(Long id, GenericEJBHome home) {
asyncId = id;
server = home;
}
public boolean cancel(boolean mayInterruptIfRunning) {
if( !cancelCalled ) {
cancelCalled = true;
// mayInterruptIfRunning only determines whether the bean method
// has visibility to the fact that the caller called Future.cancel().
if( mayInterruptIfRunning ) {
try {
//GenericEJBHome server2 = (GenericEJBHome)
// javax.rmi.PortableRemoteObject.narrow(server, GenericEJBHome.class);
RemoteAsyncResult result = server.cancel(asyncId);
if( result != null ) {
if( result.resultException != null ) {
setResultException(result.resultException);
} else {
setResultValue((V) result.resultValue);
}
}
} catch(RemoteException re) {
throw new EJBException("Exception during cancel operation", re);
}
}
}
// For now we don't even try checking to see if the task has started running.
// Just return false so the caller knows the task could not be cancelled.
return false;
}
public V get() throws ExecutionException {
// If get() has already been called, produce the same behavior
// as initial call, except if get(timeout, unit) resulted in a
// TimeoutException
if( !complete ) {
try {
//GenericEJBHome server2 = (GenericEJBHome)
//javax.rmi.PortableRemoteObject.narrow(server, GenericEJBHome.class);
RemoteAsyncResult result = server.get(asyncId);
if( result != null ) {
if( result.resultException != null ) {
setResultException(result.resultException);
} else {
setResultValue((V) result.resultValue);
}
}
} catch(RemoteException re) {
setResultException(re);
}
}
if( resultException != null ) {
if( resultException instanceof ExecutionException ) {
throw (ExecutionException) resultException;
} else {
throw new ExecutionException(resultException);
}
}
return resultValue;
}
public V get(long timeout, TimeUnit unit)
throws InterruptedException, ExecutionException, TimeoutException {
// If get() has already been called, produce the same behavior
// as initial call, except if get(timeout, unit) resulted in a
// TimeoutException
if( !complete ) {
try {
RemoteAsyncResult result = server.getWithTimeout(asyncId, timeout, unit.toString());
if( result != null ) {
if( result.resultException != null ) {
setResultException(result.resultException);
} else {
setResultValue((V) result.resultValue);
}
}
} catch(TimeoutException te) {
throw te;
} catch(RemoteException re) {
setResultException(re);
}
}
if( resultException != null ) {
if( resultException instanceof ExecutionException ) {
throw (ExecutionException) resultException;
} else {
throw new ExecutionException(resultException);
}
}
return resultValue;
}
public boolean isCancelled() {
// For now, we don't ever actually forcibly cancel a task
// that hasn't executed.
return false;
}
public boolean isDone() {
// Per the Future javadoc. It's a little odd that isDone()
// is required to return true even if cancel() was called but
// returned false. However, that's the behavior. There's nothing
// stopping the caller from still calling get() though.
boolean isDone = cancelCalled || complete;
if( !isDone ) {
// Ask server.
try {
RemoteAsyncResult result = server.isDone(asyncId);
if( result != null ) {
isDone = true;
if( result.resultException != null ) {
setResultException(result.resultException);
} else {
setResultValue((V) result.resultValue);
}
}
} catch(RemoteException re) {
throw new EJBException(re);
}
}
return isDone;
}
private void setResultValue(V v) {
resultValue = v;
complete = true;
}
private void setResultException(Throwable t) {
resultException = t;
complete = true;
}
}